The AM Forum

There are lots of Flex users and SDR advocates in the AM forum who know how to get under the hood of Power SDR and make it do all kinds of good stuff. Many of these users sound exceptional on AM because they have worked at it and figured out what works and what doesn't. Although I have studied the manual, lurked in the reflectors, accessed the official Knowledge Base, and skimmed the Flex Wiki, much of what I have learned regarding Power SDR and AM has come from discussions with others on the air. While the documentation available to Flex/SDR owners is extensive, people still seem to struggle with some areas of setup and operation. If you have conquered some aspect of Power SDR that might be a problem for a fellow AM operator, consider adding it to this thread to help someone who is starting out with one of the platforms that use Power SDR.

Audio Gain Distribution Inside PowerSDR:

I have encountered lots of Flex/SDR users on the air who sound great in every voice mode. However, it’s not uncommon to hear stations who seem to have a lot of grit, distortion, and harshness in their audio in all the voice modes. As it turns out, many of these stations are completely unaware of the multi-function TX meter and how to use it to correctly set the audio gain distribution throughout the Power SDR audio chain. It’s not unusual to find that one of the stages is inadvertently running at maximum gain while another stage is set near the minimum to compensate. This can invoke strange events such as ringing in the audio, distortion, and aggressive ALC action with pumping and audio artifacts. I certainly don’t know everything there is to know about squeezing the most out of the audio functions in Power SDR, but I did find that balancing the gain from start to finish has brought very satisfactory results for me and a number of others who were becoming very frustrated. Pages 77 and 78 of the 2.x.x Power SDR manual "sort of" infer the information given below, but I have found that many users are completely unaware of any audio level settings beyond the front panel Mic slider. Hopefully the steps below will help someone to avoid a disappointing result when they start to transmit!

1. Connect the Flex to a 50 ohm dummy load and select one of the voice modes in Power SDR. Make sure that you have a TX profile selected that has your bandwidth set as you deem appropriate for the phone mode you are using. For AM I typically create TX profiles that use 6000 or 4999 as the High setting to produce bandwidths of 12kc or 10kc on AM. The 4999 setting allows you to operate on 7.295 without encountering the “Out-of-Band” error.

2. If you have either the “DX” or “Compander” button selected on the front panel of Power SDR, unselect it now.

3. The “Mic” slider on the Power SDR front panel GUI is scaled from 0 to 70. Place it at the mid-point value of 35.

4. In the upper right corner of the Power SDR interface use the drop-down menu in the TX meter to select "Mic”. This allows you to view the level of the first audio stage of your Flex. Look at the attached picture at the bottom of this post if you are unfamiliar with the TX meter drop-down menu.

5. From the dropdown menus along the top left edge of the Power SDR interface, select “Mixer” and position it on your desktop so you can access it easily. With the Flex connected to a dummy load, key the transceiver and speak into the microphone at the voice level you typically use on the air. Observe the TX meter Mic level and adjust your level up or down with the “Mic” input level slider (or the slider for whichever input you are using) in the Flex Audio Mixer so that the maximum peaks reach no more than –2 dB. I'd like to mention that this is an absolute maximum level that I never reach while operating. I have found that I get the best results if I set this stage up much more conservatively. In fact, my levels at this stage average around -15 dB and rarely ever exceed -10 dB. As someone wisely pointed out to me recently in an email, this not "a cookie cutter" kind of thing and your setup will certainly differ from what someone else comes up with. A little experimentation and adjustment of gain levels at each stage will bring you to a very satisfactory result as long as you don't overdrive one stage and then underdrive another stage to compensate.

6. Now set the TX meter to “EQ”. This allows you to view the level of your second audio stage. From the drop-down menus along the top left of the Power SDR interface, select “Equalizer” and position it on your desktop so that you can access the Transmit Equalizer easily. I would suggest that you enable the 10 band equalizer function at this time, if you have not already done so.

7. Observe the TX meter EQ level as you speak into the microphone and adjust the “Preamp” slider in the EQ interface so that your maximum peaks reach no more than –2 dB. I'd like to mention again that the -2 dB level is an absolute maximum level that you should never exceed. In fact, with my transmit profiles I have found that I get the best results if I set this level so that my average audio rises to around -15 dB with the maximum peaks reaching to around -10 dB as shown in the picture here (http://www.w1aex.com/psdrgain/03eq.jpg).

8. Set the TX meter to Leveler. Open up the PSDR tab for DSP and go to the AGC/ALC settings page. As you transmit and speak into the mic, adjust the “Leveler” setting upward or downward from the default setting of 5 but make sure that peaks on the TX meter do not exceed 0 dB. You can further adjust the attack/decay/hang times if the Leveler is not responding quickly enough, or if it seems slow to release. This is largely trial and error, but I found the default decay and hang times to be too long, and reducing them smoothed things so that there was no audible pumping or excessive periods of gain reduction. (Pages 156 - 157 of the PowerSDR 2.x manual provide more details)

9.  Set the TX meter to ALC. Open up the PSDR tab for DSP and go to the AGC/ALC settings page. Apply audio and observe that the maximum level of peaks does not exceed 0 dB. If everything in the preceding stages has been set optimally, you should see that your maximum peaks will end up between -5 dB and -1 dB. You can also adjust the attack/decay/hang times of the ALC if you see a peak sneaking through now and then. Increase the default ALC attack time of 2 ms to a higher value and you will find that the ALC will be restrained from intervening too early. I have adjusted my profiles to the maximum allowed (10 ms) without any negative effects. Again, I found that by reducing the decay and hang times in small steps I could find a setting that resulted in smooth audio without pumping or extended periods of gain reduction. If your ALC levels are still exceeding 0 dB on peaks, use the Leveler to reduce the overall gain of the audio chain, or reduce the “Mic” level by using the slider on the Power SDR front panel GUI. A combination of both settings should allow you to keep the ALC below the 0 dB threshold. The goal here is to find settings that achieve fairly equal gain distribution throughout the software audio chain. The worst possible scenario occurs when one stage is overdriven and a following stage is underdriven in an attempt to compensate.

10.  When you have finished, your audio should sound smooth and clean. If your transmitted frequency response is not to your liking, the 10 band TX equalizer built into Power SDR works very well and is more than capable of making up for deficiencies in whatever microphone you have selected. Always remember that after you EQ your audio, you should go back through the steps to compensate for any changes in gain.

11. When you get all done with your adjustments, don’t forget to save them in a TX profile! Each TX profile saves its own bandwidth filter settings, front panel Mic setting, DX-Compander setting, EQ preamp level with either the 3 or 10 band adjustments, Leveler setting, AGC/ALC attack and decay, and RF transmit level. Additionally, starting with PowerSDR version 2.3.5 the mixer input selection and level settings, DSP TX buffer settings, VOX, DEXP, and VAC1/VAC2 settings are saved within each TX profile.  If you don’t save your settings, they will be instantly lost when you switch TX profiles! To save a profile, from the drop-down menus along the top left edge of the Power SDR interface, select “Setup”. From the available tabs that are displayed, select "Transmit". On the "Transmit" tab, in the upper left side, find the box named "Profiles". Select the "Save" button and this will bring up a dialog box that will allow you to save your new profile with a unique name. I usually select a name that identifies the mode and bandwidth for which the profile was created, but you can use whatever system works best for you.

Note regarding PowerSDR version 2.3.5:  In discussions with several others using this version it has been noted that the MIC and EQ stages seem to behave a bit "hotter" than previous versions. There's no hard data for this but just some general observations that lower settings seem to be working better. I found evidence of tearing on sibilant peaks if I allowed excursions to reach -6 dBm at either stage and it was also more difficult to keep the ALC from exceeding 0 dBm with levels that were not problematic with earlier versions. With my Flex 5000A everything behaves perfectly as long as my peak levels at both stages stay between -15 dBm to -10 dBm. You can make up the gain difference by using the "Leveler" if needed. Obviously, each installation will behave differently, so just keep this in mind if you notice either of the behaviors mentioned.

Summary:  When your levels are set correctly throughout the audio chain, engaging reasonable levels of the Compander or the DX function should result in a very significant loudness difference in your signal, without invoking the ALC or producing any signs of ringing or distortion. It's possible to produce a very decent AM signal using a cheap microphone without any external processing. My "naked" Flex 5000A runs this cheap Radio Shack electret element connected directly to the front panel mic jack:

http://www.w1aex.com/mic/mic.html (http://www.w1aex.com/mic/mic.html)

At my station, the preamplification, EQ, and compression are handled completely by Power SDR. The MP3 file below of my "naked" Flex on 75 meters was recorded by Jeff W2NBC. It's a very good sample of what a straight "out of the box" Flex sounds like with no external processing. As long as the gain is set correctly at each stage, it should sound smooth and natural. In my opinion, I don't think any other amateur multi-mode rig can match it on AM.

The AM Carrier Level Setting:

Note:  If you are using PowerSDR versions 2.4.4, 2.5.3, 2.6.4 or 2.7.2 it might be helpful to skim down the page to see the information regarding changes that were made to the AM carrier levels in those versions.

With the Flex/SDR platform, the AM mode is derived completely within the code of PowerSDR. Other than providing RF power at the end of the process, the hardware is not involved in the generation of the AM signal. In a brief description of what goes on, one of the Flex engineers explained to me that they generate a mathematically perfect double sideband signal, run it through the software DSP, and then add a carrier at the end. I don’t know much beyond that, because I’m not a software engineer, but the end result is an AM signal with the potential to produce some interesting asymmetry.

As the software evolved, the authors of PowerSDR saw an opportunity to enhance AM operation by adding a setting called the “AM – Carrier Level” which is located in the upper right corner of the “Transmit” tab in Power SDR. This setting gives you complete control over the ratio of carrier to audio as your signal is generated. If you leave this at the default value of “100” you’ll most likely find when you check your scope that you can almost reach 100% positive peaks fairly consistently and very cleanly. The interesting thing about this setting is that as you reduce its value, your Flex/SDR will begin to develop some impressive positive peaks. With a setting of “50” you will find that your carrier power drops, but your positive peaks will have grown significantly. Unlike plate modulation, you will not spray artifacts up and down the band as you adjust this setting to modulate way beyond 100% positive.

A short video of how the Flex looks on a monitor scope and how it sounds with the AM carrier level set at 50% can be viewed at the link below. The audio that you hear in the video is the Flex as it was received on a Kenwood 590S receiver with a bandwidth setting of 10 kc:  

http://www.youtube.com/watch?v=h2MXgrDIqrA

The downside of this setting is that if you overdo it some receivers that don't have synchronous detection will not take kindly to your signal. I've found that with the way my audio levels are set, AM carrier settings lower than 35% tend to cause my rig to cross the threshold to the point where it starts sounding like double sideband when detected with a receiver employing diode detection. I experimented with levels of 40% and 45% but a few voice peaks now and then would make excursions that didn't sound right. After a lot of critical listening, I found that an AM Carrier Level of 50% sounded smooth, undistorted, and loud with my settings but I suspect that it's best for each user to experiment to find the most effective level for their AM operation.

You may find that it’s really worth playing around with this feature to cleanly achieve a significant loudness factor while operating AM. Stations on the other end will no doubt inform you when you’ve gone too far.

Note regarding PowerSDR version 2.3.5:  This release of PowerSDR corrects an issue that was present in later 2.x.x versions that allowed users to generate a 100 watt carrier while running AM. Obviously, this left no head room for positive peaks so to prevent unknowing operators from generating horrendous signals on AM the engineers at Flex made some necessary changes. The short story is that an AM carrier level setting of "13" seems to correspond fairly closely to a value of "50" with previous 2.x.x versions. I've settled upon a setting of "15" and find that this results in clean and undistorted audio while producing +125% positive peaks without even getting close to the baseline. Comments from other users indicate that they have ended up with similar settings. With values below "10" my signal would occasionally begin to exhibit traces of "sideband sound" on a standard AM receiver.  

Custom Receive Filters for AM in Power SDR:

As the "Stock Filters" part of the picture below illustrates, many of the the default receive filters for AM and SAM are not really optimal. For example, why would you want a 2.4kc filter for receiving AM or SAM? It’s really easy to configure your own custom receive filters by simply right-clicking on any filter you want to change, selecting Configure, and then entering the desired data. As can be seen in the right side of the picture below, I ended up installing receive filters for 20kc, 18kc, 16kc, 12kc, 10kc, 9kc, 8kc, 7kc, 6kc, and 5kc to satisfy my uses for BCB, SWL, and AM operating. Each mode has its own filter set, so these changes will not have any effect on other modes. Of course, that means you’ll need to create filters for both the AM and SAM modes assuming you use both modes for receiving AM signals.

One other useful thing you might consider doing is to rename the VAR1 and VAR2 filters for the AM and SAM modes to something like AM-L and AM-U. What I do for these is to pre-set them to receive either the lower or upper sideband to allow me to quickly eliminate interference that shows up in only one sideband. Of course you can always do this manually in the panadapter, but I find it convenient to have this function as a single button press pre-set. With the ability to define all your own filters you can pretty much do whatever you like to suit yourself.

For a brief tutorial on how easy it is to make custom filters, take a look at the first minute of W9OY's excellent video at the following link:    

http://www.youtube.com/watch?v=E0tLtxAt24E&feature=mfu_in_order&list=UL

Remember to save your database when you finish so that you can import your custom filters back into any new PSDR versions you upgrade to.

Thanks for going to the trouble of pointing out the specific AM adjustments for PowerSDR. I haven't upgraded the software in a few years. I'm still running 1.10.4 and an older M-Audio Delta 44 sound card. The rig is used regularly but time to play is hard to find.

I recently picked up an FA-66 and I'm making some other changes like adding a Fire Wire card and the newest Power SDR software. Your tips will help during setup.

I wonder if your rack mount Power SDR GUI is an easy upgrade and if you'll share that? ;D You need to to add some rack mount washers under those screws.  ::)

Hi Mike,

Yah, I forgot to put the washers in there and have paid the price with scratches all over the virtual panel. Thankfully, Photoshop makes it easy to fix!

Lots of SDR-1000 users have tried out the 2.0.22 final release package and many like it. The new software takes some getting used to, and several settings, such as the AGC-T behave differently from the 1.x versions, but there are many enhancements. The biggest change is that they moved the ALC module to the output side of the DSP module. This eliminated issues that many users had with overshoot when driving solid-state amplifiers. If you like to play with Photoshop, you can modify the GUI interface with the 2.x versions and that adds to the fun.

I believe the guys with the SDR-1000 series can float back and forth between the 2.x and 1.x versions without any changes in firmware, so it might be worth looking at the new software to see if it suits you.

Good luck with the FA-66!

Rob

Creating Your Own "Skins" for PowerSDR:

While this is not exclusively related to AM operation, a number of smug AM Flex users have asked me about how to create custom skins like the one shown in the image above. If you are interested in messing around with this, a brief tutorial along with some custom starter graphics packs are available at this link:

http://www.w1aex.com/psdr/psdr.html

In addition to being able to design your own skins with the custom templates you can download pre-made custom skins. A few vintage examples, such as the Black Wrinkle, National NC-155, and the Collins Retro 32V skins are shown below. Mike - W8BAC collaborated on the Collins skin with some excellent photography and color setting advice. You can take a YouTube video tour of about a dozen custom skins that are available by visiting the link below. What do you make of the station that the Flex is tuned to? Is this an updated 2012 version of a shortwave numbers station with overly processed audio?

http://www.youtube.com/watch?v=U0bv_WYMck4 (http://www.youtube.com/watch?v=U0bv_WYMck4)

Have fun!

Rob W1AEX

Rob,
I just bought a second receiver module for HPSDR and doing diversity/ beam steering in software. it is very cool. I lost all my audio settings for TX so need to reload at some point. I'm actually considering a third module once the software guys proves his software works with three.

Frank,

The second receiver module coupled with the diversity capabilities makes things very interesting. I have no doubt that function will amuse you for a very long time! While you are moving forward and making things more complicated, I'm continuing down the path toward making things simpler at this place. I only have to throw about 15 switches to get on the air instead of 30 or 40. Yah... that's much better!

Flex just released the beta version of PowerSDR 2.2.2 Tuesday night. It appears to be rock solid, and they have a new tunable notch filter to go along with the auto-notch filter. The new TNF is awesome for use on AM as you can lock it to a carrier that's any distance from your operating frequency, adjust the width of the notch to whatever you want, and adjust the depth to the point where an S-9 carrier simply disappears. It's perfect for when propagation causes our QSO's here in the northeast to collide with the mid-west guys. It also will completely notch out SSB monkey chatter that shows up in either sideband, without having to remove the whole upper or lower sideband. You can make a permanent notch that stays active on any assigned frequency if you wish. That takes care of the annoying spurious crud from someone's stupid baby monitor that shows up here close to the beacon frequencies on 6 meters.

So many toys, so little time!

Good luck with the diversity/beam steering setup!

Rob

Notes regarding AM Operation with PowerSDR version "2.2.3 Final Release"

This release of PowerSDR includes the long awaited fix for the AGC problem that plagued AM users with all versions of 2.x that were released previously. At some point during the end of the 1.x versions, Flex altered the way that the AGC responded to AM signals. Instead of responding appropriately to the carrier of a signal, the AGC responded instead to the energy in the sidebands. This caused the receiver to detect AM signals in such a way that they sounded horribly over-compressed. By riding the AGC-T control, and using a very slow AGC repsonse time, users could sort of compensate when strong signals were present, but when a weaker station showed up it became necessary to constantly fuss with the AGC-T levels. Fortunately, with the 2.2.3 release Flex has fixed this so that the AGC now responds appropriately to the carrier of an AM signal and ignores the sidebands. The AGC-T level now behaves very much like an RF gain control, strong and weak AM signals sound fine together, and you can pretty much set it and forget it.

This is an important note regarding the potentially disastrous behavior of the Drive control in versions 2.2.2 beta and 2.2.3 final release while in the AM mode. Previously, the maximum carrier power with the drive control set to 100 for both AM and FM was roughly 35 - 40 watts. An AM carrier setting of 50% pretty much guaranteed that you could not inadvertently exceed a carrier power of 20 watts even with the drive control set to 100. This left plenty of head room for modulation, and made it possible to drive an amplifier without too much worry about over-driving things. When Flex completely re-wrote the FM module to add new features and to correct issues with that mode in the 2.x versions of PowerSDR, the behavior of the drive control changed radically for both AM and FM. At this time, if the AM carrier control is set to 100% and the drive control is set to 100, the Flex will produce a carrier at full output (+100 watts). This would result in a horrendous AM signal for the obvious reason that there would be zero headroom for modulation, but more importantly, this could be disastrous for those with amplifiers that only require a small amount of drive power. Keep this in mind when upgrading to either of these versions when creating TX profiles for AM and FM! Once my amplifier (2 x 3-500's) is tuned and loaded, I typically run with my AM carrier setting at 40% and my drive level set between 15 and 30 to run anywhere from 150 watts to 250 watts of carrier power depending on conditions. When modulating heavily, I see peak power reaching between 1000 - 1500 watts regularly and the scope reports a healthy looking signal.

Rob W1AEX

Regarding the "Limit Slew" setting in PowerSDR 2.2.3

In previous versions of PowerSDR some users have encountered issues when driving an amplifier with their Flex 5000/3000 hardware. Certain amplifiers have randomly tripped when keyed, and sometimes when unkeyed. The Acom and Tokyo High Power amplifiers seem to be particularly sensitive to this although users with grid-driven amplifiers have also reported the issue. Flex studied the problem and even re-wrote the code in PowerSDR to alter the position of the ALC module in the TX chain to fix this. They did seem to resolve the issue when the amplifier was being keyed, but the unkey problem still remained. After much experimentation they appear to have corrected the issue. Although I haven't seen any sign of the "Limit Slew" setting in the release notes, it appeared without a lot of fanfare in the 2.2.3 version of PowerSDR. On the "Transmit" tab underneath the "AM Carrier Setting" you will find the toggle box for this setting. If you hover your mouse cursor over the toggle box a brief explanation of the function of this setting will appear, as seen in the image below.

A friend with an Acom amplifier was on the verge of selling his Flex 5000A due to the "tripping" issue. He employed every trick he could think of to overcome the problem but was unable to resolve it. The amplifier manufacturer acknowledged the problem but offered no thoughts on what might be done to overcome it. The folks at Flex listened and came up with the "Limit Slew" resolution that cured the problem completely even with stubborn cases such as his. So, by using the "Antenna" form to select the best keying delay, and toggling the "Limit Slew" setting to softly unkey the amplifier, you should be able to find a combination that will work even with the most sensitive of amplifiers.

Of course this whole thing is a non-issue for my pair of 3-500's which don't flinch no matter what I do, but the "Limit Slew" option makes operating AM or any other mode possible with even very sensitive amplifiers.

Rob W1AEX

I am not an owner of a Flex radio, nevertheless I see that AM configuration is very poor. With a SDR system it should be possible to select between constant carrier and controlled carrier with controls for: residual carrier, carrier decay time constant, single side band AM (carrier with one sideband), minimum power of the envelope, maximum power of the envelope, a selection of RF envelope clipping algorithm, etc.  Analog AM has solved most of these issues, now just put them in software....
If these options are already available, please let me know, maybe I will buy a Flex radio.
Tnx

IN3IEX,

I don't work for Flex so I can't really comment on the "features" you are looking for or the "issues" you are focused on. You might want to join the Flex Reflector and present your thoughts to the Flex hardware and software engineers.

73,

Rob W1AEX

Join Flex Reflector here -   http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz

Notes regarding AM Operation with PowerSDR version "2.3.5 Final Release"

There were a number of changes made to this version that require some attention when running AM. When things are set correctly, this version behaves beautifully, so don't be afraid to give it a try. If you decide you don't like it, the 2.2.3 version works just fine with the new firmware that is installed with the 2.3.5 release. You can simply start up the earlier version and it will behave like it always did. The list below briefly addresses changes that have been noticed:

1. As noted in the "Audio Gain Setup" article above, a number of users have mentioned that the first two audio settings at the MIC and EQ stages seem to behave a bit hotter. You may find that you have to back the Mixer and EQ gain sliders down a few notches to smooth things out. More details are noted in the Audio Gain Setup article.

2. As noted in the "AM Carrier Level" article above, the engineers at Flex corrected the issue with excessive carrier output power while running AM. The maximum carrier output power in early versions of 2.x.x was limited to around 40 watts of carrier, however, at some point this function was broken and it was possible to run 100 watts of carrier power in AM. Obviously, this left no headroom for modulation. To correct this, the maximum setting that can be entered in the AM Carrier Level field is now 50, and the default is 25. More details are available in the "AM Carrier Level" article above.

3. The most important change in my opinion is that many more settings have been moved into the "TX profile" region of the database. Most notably, the "Mixer" settings and the "Buffer" settings are now saved into each individual TX profile. This it a huge step forward and adds a lot of customization to each profile. With AM, the ability to swap buffer settings on the fly gives you the ability to change the behavior of the DSP transmit filter by simply switching TX profiles. The first picture below illustrates a 10KC profile using a TX buffer size of 4096 that creates a vertical brickwall effect. This is perfect for working in a crowded area of the band, but it can produce some harshness in the audio due to the abrupt cut-off. The second picture shows an identical 10KC profile using a TX buffer size of 512 that creates a much softer filter skirt. The gentle filter completely eliminates the harsh sound of the abrupt cut-off seen in the previous filter. With my setup, I did find that a buffer size of 512 introduced a noticeable garbling effect into the audio, so after some experimentation I settled on 2048 for my AM profiles. This is really worth playing around with as it allows a lot of flexibility of operation.

If you give the 2.3.5 version a try I don't think you'll be interested in going back to the earlier versions.

Rob W1AEX  

Using the PowerSDR I/Q Recorder to Listen to Your Transmitted AM Signal

Unfortunately, the way the “Monitor” function is implemented in PowerSDR, you can’t listen to your transmitted AM signal in real-time as you can with SSB, however, it is possible to hear what your AM signal sounds like by using the “Recorder” function of PowerSDR. By setting the recorder to make a pre-processed I/Q recording, you can view your transmitted signal in the pandadpater and listen to your actual transmitted audio. This is very useful for checking your audio for distortion, clarity, and tonal balance. The setup for accomplishing this is very simple:

1.  From the menu choices along the top left of PowerSDR select Wave.
2.  This produces a settings box named Wave File Controls where you should select Options.
3.  In the Wave Record Options box select Pre-Processed Audio for the Receive setting.
4.  We won’t be re-transmitting what we record so ignore the setting for Transmit.
5.  Click the “X” in the upper right corner of the Wave Record Options box to close it

Note: The pictures at the bottom of the article may help with the setup instructions above.

When those settings have been made, in the PowerSDR GUI select the AM transmit profile you want to sample and select SAM for the receive mode, then press the Record button in the Wave File Controls box. As the recorder is running, key the transmitter to make a test transmission. I would suggest that you wait about 5 seconds before you start speaking. The reason will become clear when you read the playback instructions below. At the conclusion of your test transmission, press the Record button again to stop the recorder.

To play back the recording you made, press the Add button in the Wave File Controls box and browse for the recording you just made. It will be time stamped so it should be very easy to locate. After selecting the correct file, check to make sure that you have PowerSDR set to receive with a bandwidth that matches your transmitted bandwidth. When everything is set, press Play in the Wave File Controls box. Because there is an 11 KHz offset when you transmit, your recorded signal will not be on the frequency you are listening on. Simply press the “0 Beat” button repeatedly until it locks in. Note that the reason for waiting a few seconds before speaking when you made the recording was to give you time to get the signal centered in the receive passband for playback. Adjust your AGC-T and Volume settings and take a listen to how you sound. What you hear is an excellent recording of what your signal sounds like when you are transmitting. What you see in the panadapter will give you an indication of the peaks and valleys in your transmitted frequency response as well as an indication of your transmitted bandwidth.

The link below is a video recording of my Flex playing back a recorded I/Q file of an AM test transmission. You’ll see at the beginning of the recording that it took 6 presses of the “0 Beat” button to get my transmitted signal into the passband and centered.

http://youtu.be/WtOGzfnu-Ho

In the second video recording, I used the I/Q recording feature to help set up the compression levels for a Marshall MXL-770 studio condenser microphone that I plugged into the balanced input on the back of the Flex 5000A. It was very easy to see and hear when the software compressor reached the point where the audio began to fall apart.

http://www.youtube.com/watch?v=po_kyIqgHdI

Although you can’t monitor your AM transmissions in real-time, the I/Q recording function built into PowerSDR can be used to give you an excellent “air check” of your AM signal. For real-time monitoring, a simple RF sampling monitor (http://www.w1aex.com/756AM/RFsamp.jpg) can be built with a handful of parts, but to be honest, the I/Q recordings reveal much more about your signal.

Nice job on this Rob. I am in the process of upgrading to a 5K and will be using your new technique for my new installation. I also like your article regarding the new gaming computer. Have you used the new box for Power SDR yet and if so, how dose it work?

Thanks for everything, Keep up the good work.

Mike

Hi Mike,

I think you'll enjoy the simplicity and reliability of the Flex 5K hardware platform. It's pretty much plug and play at this point. I did run the Flex with the new computer for about a week as I did some cleanup work on the retired gaming computer and it ran PowerSDR very well. The retired gaming computer that's handling Flex Radio duties now is based upon a four year-old Intel dual-core Pentium (Wolfdale e8400) running @ 3.0g that handles PowerSDR very smoothly. Hopefully, it will keep running for a few more years!

Are you planning any options for your 5K? Mine is stripped, no second RX, no VHF/UHF, no ATU, and I have to admit that I have no interest in adding any options in the near future. My big project now is to finish up restoring a 10 year-old Hex Beam. If I can get a couple of decent days in a row I'll be able to finish and move it to the top of the tower without too much effort.

Good luck with the new Flex!

Rob

Notes regarding AM Operation with PowerSDR versions "2.4.4 through 2.6.4 Final Releases"

The move to version 2.4.4 or any later version represents a major release for PowerSDR with a huge change in performance for the Flex 3000 and Flex 5000 that utilize a firewire interface. With these versions, Flex is using a completely new firewire driver with all new dependency drivers and a new firmware version to accommodate the new driver architecture. One very important thing to understand about upgrading to either of these versions is that once you upgrade, you will not be able to load earlier versions of 2.x.x unless you completely uninstall version 2.4.4 (or later) and follow a fairly convoluted procedure (involving older firewire drivers and firmware) as detailed in the release notes. Fortunately, if you export a copy of your 2.3.5 database before you upgrade, you can use the SDRTranfer utility to import your settings into version 2.4.4 (or later) and it should work perfectly. This makes the upgrade completely painless as all your old settings (TX profiles, band stack registers, custom bandwidth filters, etc) will be there without any fuss. Note that you need to uncheck the "Strict DB Import Compliance box" (Look in Setup>Options at the bottom of the tab) to allow importing from a previous version. Another good thing is that once you move to version 2.4.4 or later you probably won't want to go back!

The new firewire driver eliminates issues with DPC (Delayed Procedure Calls) that plagued some users with computers that exhibit high latency as a result of hardware and driver variables from assorted combinations of peripherals and motherboards. This eliminates audio glitches and subsequent distortion that some users experienced after a DPC event with their computer. The new streaming driver has the ability to function with a latency factor that approaches 0 ms making it very close to real-time. If you have experienced the disconcerting sound of your voice arriving late while you monitor your transmitted audio you know what this is about.

The next change is relevant to all Flex hardware that is used on AM. Flex has corrected the scaling error that has been evident with the AM Carrier Level setting for most of the 2.x.x releases. They also added the ability to fine tune this setting by increments of .1 if desired. You will almost certainly find that the AM Carrier Level setting that you used in version 2.3.5 or any other earlier 2.x.x version will require adjustment. Your results may vary from mine, but using my scope to adjust the AM Carrier Level it was very easy to arrive at the following settings for my Flex 5K:

100% modulation with 10 watts of carrier:   Drive = 20 --- AM Carrier Level = 45
125% modulation with 10 watts of carrier:   Drive = 25 --- AM Carrier Level = 40
150% modulation with 10 watts of carrier:   Drive = 30 --- AM Carrier Level = 35

I generally run my AM profiles to generate a signal that has the potential to hit a maximum of 125% positive peaks and find that this produces a smooth sounding signal that is compatible with most receivers that employ a standard diode detector. If you get reports that your Flex sounds distorted or gritty on modulation peaks it's possible that you might have the AM carrier level set too aggressively which translates as a number that is too low. Note that while you are setting this, you should keep an eye on the PowerSDR TX Meter (set to ALC) to assure that your audio levels remain below -2dB on peaks. Assuming that each audio stage in PowerSDR is adjusted correctly (see Audio Gain Distribution Inside PowerSDR in an earlier post above if you are not sure) the transmitted audio should be absolutely clean. When everything is adjusted optimally, whatever audio you put into your Flex is exactly what will come out of it!

These two versions look like excellent releases of PowerSDR for AM, but as always, it would be very wise to read the release notes before upgrading to this version. The links below will download each version's release notes in a PDF file with everything you need to know. Note that it's not necessary to install version 2.4.4 if you want to go directly to the 2.5.3 version.

Version 2.4.4  http://support.flexradio.com/Downloads.aspx?id=402 (http://support.flexradio.com/Downloads.aspx?id=402)

Version 2.5.3  http://support.flexradio.com/Downloads.aspx?id=411 (http://support.flexradio.com/Downloads.aspx?id=411)

Just remember that it's not an easy process to go back to an earlier version once you move to PowerSDR 2.4.4 or 2.5.3 but to be honest, I can't imagine why you would want to take a pass on the huge performance increase in these new versions.

Rob W1AEX

NOTE ADDED 11-10-2012:  The computer that I have been using with my Flex was loaded with Windows XP/SP2 when I updated to version 2.4.4 of PowerSDR. Several times over the past month I had a DRIVER_IRQL_NOT_LESS_THAN_EQUAL issue with the legacy Windows XP "ohci1394.sys" driver when PowerSDR 2.4.4 was running concurrently with programs that accessed the sound card heavily, such as Camtasia or Adobe Audition. I emailed Flex and they replied to me in less than 3 minutes. As it turns out, if you are retro like me and running Windows XP it is necessary to move to SP3 to avoid issues with the new Flex streaming firewire driver for the 2.4.4 version of PowerSDR. It is also necessary to have NET Framework 3.51 (version 3.5 + NET framework 3.5 SP1).

Free Band Text Editor for PowerSDR from Ray - K9DUR

This is a very slick program that allows you to insert the established AM operating frequencies or AM windows on any band. There's nothing worse than seeing 75M SSB in the "Band Text Field" as you're having a nice AM conversation with your buddies. Now you can set ranges of frequencies or individual frequencies to be labeled however you want them. It took me less than 10 minutes to label every band with my AM operating areas. Note that the "BandText Editor" only works with versions of PowerSDR that use the .xml format file for the database. This means it is compatible with PowerSDR version 1.18.1 and all the 2.x.x versions that followed.

Over the years Ray has written some very nice utilities for managing the PowerSDR database files and this is another fine piece of work. The software is available for free from his site at the following link:

http://k9dur.rnaconsultingservices.com/Downloads.aspx

Ray generously offers his software utilities for free but you might want to consider sending him a few bucks if you enjoy what he has created.

Rob W1AEX

Hi Rob,

Trying out my new Flex 1500 into the dummy load while monitoring on a 'scope was producing terrible AM. Carrier dropping with modulation just as you noted in a post on the FlexRadio Forum 2 years ago.
http://forums.flexradio.com/Topic3515-56-1.aspx?
After much trial and error I got my 1500 to work by setting the "Mic" gain at "0". Yes, ZERO! Then brought the Audio Mixer up to near Max, the Drive about 50 and get 1 watt of what appears be be actual AM and not some weird inverse controlled carrier AM. I don't know if others have found this trick or not but I could find no reference to it anywhere. I'm posting it here in hopes that it may save some other unfortunate soul the hand wringing, teeth gnashing, and garment rending that I went through to figure it out.

I still don't know if I have it where it should be but it looks good on the scope and my cheap PEP watt meter now swings up with modulation instead of down. The Flex article on how their ALC works explains the mechanics of it but not the particulars for this radio. Your posts in this thread are much better in relating to actual settings but pertain mostly to the 5000. So this is for the 1500 guys. Hope it helps.

Don
KK4YY

Don,

Thanks for posting the info for the 1500. I have a 1500 I'd like to try on AM. You saved me from posting a question regarding some ballpark settings to start out with. I'll give yours a try and let you know what happens.

Thanks,
Dave
KX9DK

Don,

Thanks for posting this information on the 1500 anomaly with AM. This will definitely help the guys who encounter the issue where the carrier and modulation interact inappropriately. I know this drove Pete W1VZR crazy a couple of years ago. It seems that a setting of "0" with the MIC slider actually sets the gain for that stage to "0" rather than dropping the audio level to "none". The first guy I ran into who used this to advantage was Craig W1MSG who wrote an article about it to explain how he overcame an audio anomaly he encountered when using an external rack with his 5000A:

http://w1msg.net/media/blogs/a//Flex5000.pdf

I'm guessing that your conclusion about ALC interaction is spot-on as PowerSDR apparently monitors audio levels at the MIC stage and based upon levels it sees there the ALC will intervene, sometimes inappropriately when it comes to AM with the 1500. That's great news that you have found a way around this! Thanks again for sharing your findings.

73,

Rob W1AEX

Rob,

I just "discovered" this thread.   Great job putting it all down on paper. It will help us SDR Newbies a lot.


I'm getting back to my HPSDR project maybe next week, so will read it over and go from there.


It's a lonely whirl, writing these help articles,  and we need a slap on the back once in a while...  ;D  [SLAP!]

T

Hey, thanks Tom! Make sure you add your findings as you discover them when you roll up your sleeves and get busy again with the HPSDR project. It's my understanding that there are some notable differences between the Flex version of PSDR and the version that has been adapted for use with the HPSDR platform. Items that are specific to setting things up with the HPSDR hardware would be helpful to those who use the HPSDR hardware on AM. Nag Frank GFZ to document some of his HPSDR kung-fu as well!

Rob W1AEX

(Updated)
I've been using an Apache Labs ANAN-10/Hermes SDR with PowerSDR OpenHPSDR mRX v3.1.5 and ANAN-100D/Angelia SDR with PowerSDR OpenHPSDR mRX PS v3.2.8 on AM for a few months now, in conjunction with an REA Modulation Monitor.  I operate mainly on 10M and 15M.

You must initially set proper audio levels watching the meter in MIC and EQ positions.  My goal is -5dB level on voice peaks.

To assess your tx audio equalization, use the built-in wave recorder/player with PSDR "Dupe" engaged, so that you are recording what is being transmitted and received.  Without "Dupe", you are just recording the audio input going to the transmitter.  Recheck the EQ meter level after any changes.

You then must set the carrier level control to optimize the modulation level.  You want to be just hitting 100% negative - needle shouldn't be slamming into and staying at 100% negative.  I'm finding that this setting varies greatly from band to band.  I therefore save different transmit profiles for each band.  Every person you ask will give you a different answer for proper carrier level setting.  With the REA Modulation Monitor, I find that optimal carrier level settings go from about 70 on 10M down to about 40 on 160M.  These settings provide 100% negative modulation and 100-130% positive modulation.  [update Jan2015: this step no longer necessary with PSDR v3.2.19 and later - just leave carrier level at 100]
I  typically transmit with 4KHz wide audio in AM mode and consistently receive rave reviews on the tx audio/modulation quality.

73, Barry N1EU

I wanted to add a few additional tips using PowerSDR OpenHPSDR with ANAN/Hermes/Angelia.

Leave the front panel Compressor OFF.  It causes serious audio degradation.  Don't even use it in ssb.

DO use the Leveler.  Enable it under setup-dsp-AGC/ALC.  I set it for 10dB and didn't touch the default timing settings (attack 2msec, decay 500msec, hang 500msec).

I have found very mixed results using the ANAN mic and line inputs.  If it works for you, great.  What I did find to work VERY well and delivered a noticeably cleaner sound was to use a Focusrite 2i2 external audio interface.  It is a high quality mic preamp coupled with a high quality soundcard in a small box with 2 XLR inputs and a USB cable to connect to the computer.  It also has balanced line level inputs/outputs and phantom power that I don't use.  I connect it via VAC to PowerSDR under setup-audio-VAC1.  Enable it, shoose ASIO driver and Focusrite Input.  My other settings are Buffer 2048, 96000 Sample, Stereo, 8dB TX Gain, Combine VAC Input Channels, Stereo and 120msec Buffer Latency.  I'm admittedly no expert on these settings but this is what works well for me.

Here's a video of Carlos CT4RK's very cool vintage shack while he tuned my ANAN's s9+ 10M signal in on his Geloso G4/214 :  http://www.youtube.com/watch?v=-rNzDCw8oZU (http://www.youtube.com/watch?v=-rNzDCw8oZU)

73, Barry N1EU

Nice shack, nice receivers!

My ANAN-100 Hermes based Apache Labs rig has been on my operating bench for 10 days now and I've had the chance to run quite a bit of AM with it. Unlike the VAC approach that Barry - N1EU is using, I ran my hardware audio chain through an Edcor 1:1 600 ohm transformer into the unbalanced rear panel audio input connection. That approach has worked cleanly for me and I have experienced no issues with RF feedback on any band at any power level. The performance has been every bit as good as I had hoped it would be and the changes that Warren NR0V and others have made to OpenHPSDR mRX have been really good ones for AM. The audio levels could not be simpler to optimize and as far as I can tell it's close to impossible to drive the transmitter beyond 0 dB on the ALC meter with any voice mode. As long as you set the mic/line input level, eq level, and the leveler to undistorted settings it will cleanly and faithfully transmit whatever your TX audio source is.

The links below will take you to a pair of videos with the first one showing my ANAN 100 injected with a 1000 cps tone to produce a sine wave and the second showing obvious asymmetry while transmitting with voice. I chose an AM Carrier Level setting of 70 for these videos but have found anything in the range between 70 - 80 to be very clean and loud sounding.

https://www.youtube.com/watch?v=dCJpenhEyx4

https://www.youtube.com/watch?v=aNrKCXeiveY

The pictures below are snapshots from the two videos. The first one shows a 1000 cps sine wave reaching beyond 100% positive as it approaches the baseline in the negative direction. Note that when you select an AM Carrier Level that is less than 100 you enable the transmitter to produce this kind of asymmetry. The second picture shows the asymmetry that can be developed effortlessly with voice modulation. I haven't yet received an audio "air check" recording of the rig during a QSO on AM but the reports I've received have been very positive. The third attachment below is a short mp3 made with the audio recording function of the SDR-Console software that I use to run my Fichten Field Day SDR. It gives a pretty good idea of what the transmitted signal sounds like in spite of the heavy AGC action due to proximity effects.

Rob W1AEX

A remarkable feature that has been implemented in the OpenHPSDR mRX software is the ability to run pre-distortion linearization with AM and SSB. This protocol is named "Pure Signal" and its ability to improve transmitter IMD is impressive. Once the user has calibrated the power table in OpenHPSDR mRX so that the PA produces 100 watts output from 160 - 6 meters all that is required is to optimally set the sampling level for each band to allow the algorithm to remove transmitted distortion products. The effect is very dramatic with 3rd order IMD improving from a fairly typical level of -30 dB to around -50 dB.

The video below shows my ANAN 100 transmitting a 10 watt AM carrier while being received by an SDR across the room. If you watch above and below the 10 KHz wide transmit bandwidth, you can see the effects of pre-distortion linearization on the signal. Note that the received audio has some grit due to a recording level issue in Windows 7 that I have not yet resolved. The ANAN actually produces very clean audio when transmitting. At any rate, it would appear that the pre-distortion linearization protocol really helps to produce a very neighborly AM signal.

https://www.youtube.com/watch?v=o8h6ParzsAs

The two pictures below are screenshots from the video that demonstrate the difference when "Pure Signal" is toggled on and off.

In my setup, at this time I am only optimizing the IMD of the ANAN itself. By using an RF sampler at the output of a linear amplifier and bringing that sample back to an RX port on the ANAN rig the "Pure Signal" algorithm will also correct distortion produced by the amplifier as well. Those who are using receivers with spectrum displays can easily spot the amazingly clean signals where this has been implemented.

Rob W1AEX

Great report as always Rob.

Do they have a way to include an outboard final AMplifier within the pre-distortion loop?

Yes, but you have to fashion some sort of RF Sampler at the output of your amplifier.

Thanks Barry.

After doing some troubleshooting I was finally able to resolve the distortion issue that plagued my video capture software after my migration to Windows 7. The direct stream audio captures heard in the videos are a good representation of what the ANAN sounds like and the video capture of the GSDR panadapter gives a good representation of the signal's occupied spectrum characteristics. The two links below are videos that were made with the ANAN-100 transmitting into a dummy load as the FiFi SDR received the signal while the Video/Audio capture software was used to make direct stream recordings.

ANAN-100 transmitting AM with a TX bandwidth of 10KHz  https://www.youtube.com/watch?v=tJk36tWxmpw&feature=youtu.be  (https://www.youtube.com/watch?v=tJk36tWxmpw&feature=youtu.be)
ANAN-100 transmitting SSB with a TX bandwidth of 3KHz  https://www.youtube.com/watch?v=MCm3mKHyuAo&feature=youtu.be (https://www.youtube.com/watch?v=MCm3mKHyuAo&feature=youtu.be)

Keep an eye on the filter edges and on the spectrum around the transmitted signal when pre-distortion is active. The pre-distortion linearization correction can be wrapped around the output of an amplifier by inserting a directional coupler at the output of the amplifier and bringing an attenutated RF sample back into one of the ANAN's RX ports. Last August the ARRL acknowledged Warren Pratt - NR0V for his development and implementation of the pre-distortion linearization module in the OpenHPSDR mRX software as they presented him with the 2014 ARRL Technical Innovation Award. I definitely love what he has done and also love transmitting splatter-free!

Rob W1AEX

Great post as always and maybe the concept will spread to the rest of your state  ::)

Wow, nice job with the video and the transmission Rob!

I'd love to see/hear how a Flex 6000 would do on AM in comparison to the ANAN-100.

73, Barry N1EU

Thanks for the comments Dave and Barry. From what I have heard on the air the Flex 6.xxx rigs have the potential to sound every bit as good as anything out there. The only Flex 6.xxx owner that I have heard on AM is Alan K2WS and he sounds very nice on his. There is a recording of his signal as it was heard last winter on 10 meters at this link:

https://www.youtube.com/watch?v=3zNhBRa0imU (https://www.youtube.com/watch?v=3zNhBRa0imU)

That was recorded almost a year ago (last October) so SmartSDR was not as evolved as it is today. If I can catch Alan on the air I'll definitely ask him if I can make a recording so that I can add the Flex 6.xxx to my collection of videos. Depending on how SmartSDR comes along I will probably end up playing around with one of the Flex 6.xxx series but I have to admit that the ANAN is so feature rich that I have no interest in parting with it yet!

73,

Rob W1AEX

The video at the link below shows CuSDR 64-bit running my ANAN 100. This is version 0.3.2.14 which is the latest publicly available beta copy of this software that at this time is capable of only receive functions. This beta version is a little rough and was simply released to give people an idea of what is to come when more mature versions are forthcoming. The developer is currently implementing TX functions into the software, complete with the pre-distortion linearization protocol that is currently available in OpenHPSDR mRX. In the video, the software is running 3 slices that include an AM broadcast station, an AM QSO on 40 meters, and some long haul utility aviation traffic being handled by one of the NY Advisory stations in the 8 MHz band. In the first screenshot the slice interface is opened up to change the bandwidth of the slice tuned to the AM broadcast band. In the second screenshot you can see some pretty bad IMD present in the waterfall that is displaying an upper sideband signal from an aircraft communicating with NY Advisory. Under the link below are some notes about the contents of the video.

Rob W1AEX

https://www.youtube.com/watch?v=jlJZEft1Ci4

Watch at 720p for best clarity. Currently, CuSDR64 can run 5 RX slices along with the full spectrum panadapter under the frequency and s-meter panel. When the 1 gigabit ethernet firmware upgrade is completed my ANAN-100 will be able to display 7 slices. Each slice can be un-docked from the main display if desired and placed anywhere on your desktop. To switch to one of the RX slice audio streams simply click on that slice display. In this video, the main window is tuned to 0.880 MHz WCBS in NYC with one slice set to receive a 40 meter AM QSO and the other slice set to receive NY Advisory as it directs air traffic through its air space. There are differences in RX gain as you move from slice to slice which I believe is due to different bandpass filters being switched into line in the ANAN-100 as it moves to different frequency ranges. Note that at 5:30 into the video you can observe an aircraft transmission that exhibits severe splatter issues due to an issue with the transmitter in the plane. Looks like something is overdriven with resultant IMD problems.

That pre distortion looks amazing!
Pick the bandwidth you want and no matter what you do its not going wider.
TX 1 Hz square waves and so on, truly amazing.

Rob, as far as I can tell, tx capable cuSDR is pure vaporware and some folks have privately told me they don't think it is ever going to happen.  I guess we'll wait and see.

73, Barry

Brett - I am amazed at the way pre-distortion removes distortion inside the bandpass as well as outside the intended transmit bandwidth. I am hoping that the developers are able to refine the implementation to make it easier for the non-technical guys to run it. Not that it's difficult to set up but it's a little intimidating for the plug and play operators.

Barry - A couple of months ago I found a small bug in CuSDR and posted it to the yahoo group to see if anyone else noticed it. Within a couple hours of posting it I received an email from Hermann, who is leading the development of CuSDR, thanking me for bringing it to his attention. He mentioned that the only major obstacle to quicker development is the amount of time he can devote to the project. It is my understanding that he is collaborating with Warren and others in the OpenHPSDR community to implement the new DSP engine and the pre-distortion protocol. The actual interface for CuSDR is pretty much done. The release of the gigabit ethernet driver/firmware for the ANAN main boards is also an important factor in pushing the functionality of CuSDR (and OpenHPSDR) to its maximum. I know they have a working gigabit driver and firmware but have no idea if they have it out there for the alpha testers yet. There is no timeline but I would not be surprised if an updated pre-alpha type release comes out in the next 6 months for people to play around with. I'm very content to play with OpenHPSDR for the time being!

73,

Rob W1AEX

Just a note that in recent versions of OpenHPSDR PowerSDR (3.2.19, 3.2.20), I don't seem to see the need to adjust carrier level.  With the default setting of 100, I'm seeing 100% negative and 150% positive modulation on the REA mod monitor.

73, Barry N1EU

Where did you come across these versions? The latest I've seen on the flex site is 2.7.2. Is there another source for early release versions?

Kevin, WB2EMS

Sorry, I'm speaking of the OpenHPSDR version of PowerSDR that runs on Apache Labs and OpenHPSDR hardware.

Looking back at my posts in this thread, there's some outdated info.  I've got the latest audio setup info that is working well for me and recommended by others at http://anan-100d.wikidot.com (http://anan-100d.wikidot.com)

73, Barry N1EU

Using the excellent K9DUR software, not only did I change the band text for 3870-3890 and 7280-7300 kHz to "AM Window" -- I also replaced the term "SSB" wherever it appeared with the more appropriate term "Phone."

73,

Kevin, WB4AIO.

I get a 404 error with that link.  I believe the correct link is http://k9dur.rnaconsultingservices.com/powersdr_utilities.html (http://k9dur.rnaconsultingservices.com/powersdr_utilities.html)

I thought it might be something like that. Can Open HPSDR run on the flex radios?

Kevin, WB2EMS

No, and you have to appreciate the irony in Flex creating something that other folks ran with and Flex cut themselves off from.

For those who are interested in learning more about the hardware, software, setup, maintenance and modifications for the Apache Labs ANAN transceivers visit the Wiki that Barry - N1EU has put together at the following link:

http://anan-100d.wikidot.com/

The volumes of information he has collected there would be helpful to prospective purchasers as well as current owners.

Rob W1AEX

The OpenHPSDR mRX PS software used with the TAPR and Apache Labs ANAN rigs offers a feature called adpative pre-distortion linearization (APD) referred to as "Pure Signal". When an RF coupler is installed at the output of a station's linear amplifier and an attenuated RF sample of the amplified signal is returned to the ANAN hardware the algorithm used in OpenHPSDR is capable of substantially reducing IMD throughout the entire transmitter chain. It is not unusual for stations employing APD to produce signals exhibiting IM3 better than -50 dB.

In the video at the first YouTube link below you can see what Pure Signal does to the 10 kHz wide AM signal of Chuck K1KW following his installation of the "wrap around" hardware and the proper adjustment of the Pure Signal software settings. Chuck is running his ANAN-100D into an 8877 and producing an amazingly clean signal on 40 meters. In the panadapter, watch the area on both sides of his transmitted signal when Pure Signal is toggled on and off. The waterfall view presents a nice view of the absence of IMD artifacts when Pure Signal is engaged. The second link shows what Chuck's signal looks like with and without Pure Signal APD while running a 3 kHz bandwidth on SSB.

The link directly below shows the components I needed to implement pre-distortion linearization. The block diagram illustrates the station setup with an external coupler and relay installation that is used to wrap Pure Signal around my entire transmitter chain. Note that current production ANAN rigs no longer require an external relay as the newly designed PA board uses an internal relay to route the sampled signal to the RX input:  

http://www.w1aex.com/anan/anan.html#relay

With Pure Signal APD a big signal can also be a very neighborly signal to stations on adjacent frequencies!

73,

Rob W1AEX

https://www.youtube.com/watch?v=TtbNBHhVqeo    (AM video)

https://www.youtube.com/watch?v=xIimiVMmhmM    (SSB video)

In the first week of August (2015) the Zeus Radio SDR manufacturers announced their intention to make the SDR software used by their Zeus Radio hardware compatible with the Apache Labs ANAN hardware. Since then several beta versions have been released with added functionality for the ANAN products. The software is very nice looking and has a lot of clever GUI enhancements such as being able to undock the panadapter/waterfall from the control panel and on-the-fly sampling rate changes (from 48k to 384k) simply by grabbing the frequency band between the panadapter and waterfall with a right mouse click and moving left or right. The current beta has TX and RX capability and offers a very complete built-in voice processing package. Transmit bandwidths are variable from 2kc to 10kc for AM and 1kc to 5kc for sideband. In addition, there is native support for VST plugins in the Zeus Software. There is also a pre-distortion linearization module implemented in the software but I am not aware of anyone with ANAN hardware that has tried that out yet. Note that the software does not appear to recognize the hardware MIC and LINE transmit audio inputs of the ANAN radios but instead relies on software derived audio. I'm certainly no expert with this software package but I did mess around with it a bit and made a few videos for those who are interested:

Setting up the TX audio levels for AM:     https://www.youtube.com/watch?v=-0IFU2bcGX0 (https://www.youtube.com/watch?v=-0IFU2bcGX0)

Tuning around the AM broadcast band:      https://www.youtube.com/watch?v=t4Q1EHi21iE (https://www.youtube.com/watch?v=t4Q1EHi21iE)

This project is kind of a moving target as Zeus Radio coders release new beta versions with more features enabled. Should be fun to explore what they are able to do with this. Another interesting development is the announcement by Simon Brown that he is implementing full TX/RX support for the ANAN line of transceivers into SDR-RADIO version 3.0 with a targeted release in the first quarter of 2016.

Rob W1AEX

Interoperability is a great idea. And it sounds like they are doing some real creative work there.

But only 5 kHz of transmit audio bandwidth? That's disappointing. There's no reason on God's green Earth that we shouldn't get at least 10. Since getting an SDR, I try to get at least 7.5 kHz if at all possible when using high quality modes.

73,

Kevin, WB4AIO.

Rob said it has 10KHz AM tx bandwidth, ja?

I recently started connecting my external hardware audio chain to my ANAN through a UMC202HD digital interface. I was amazed at the simplicity of this approach and also how clean it sounds while running the AM mode. Many others have been doing this for a long time and I was reluctant to deal with the whole latency problem that I heard others describe but after reading the DAW Setup tutorial by Scott - WU2O it seemed like a good time to give it a shot. Scott's PDF tutorial is hosted at the ANAN Wiki site created by Barry - N1EU and can be downloaded here:

http://anan-100d.wdfiles.com/local--files/home%3Ahome/ASIO_DAW_setup.pdf (http://anan-100d.wdfiles.com/local--files/home%3Ahome/ASIO_DAW_setup.pdf)

Following the recommendations in Scott's tutorial I was able to set up my UMC202HD interface in a few minutes. Starting with conservative values for the streaming mode, VAC bufffer size and VAC latency it was a simple process to move to lower and lower latency values in steps. I quickly reached the point where I can no longer hear any latency at all when I monitor my own transmissions through OpenHPSDR. I have not experienced any audio dropouts, glitches, or anomalies of any kind in any voice mode while running through the digital interface. Details of my modest setup can be seen at the link below:

http://www.w1aex.com/anan/anan.html#digital (http://www.w1aex.com/anan/anan.html#digital)

The advantages I have observed are that you don't need to fuss with the DB25 input on the back panel of the ANAN, no 1:1 coupling transformer is needed, any RF feedback that you might be dealing with will probably be eliminated, and once you have the interface up and running it opens up a whole new world of voice processing with DAW software and a flood of free VST plug-ins. Scott's tutorial goes into those depths if you wish to pursue that path. I'm just going to keep it simple for now!

Rob W1AEX

Good stuff Rob!  The down side is that you're subject to the vagaries of Windows computers and hunks of software sometimes not playing nice with each other   :o

I wholeheartedly endorse getting as far away as possible from that DB25 though!!!

Barry N1EU

Barry,

That was one of my fears, but even my 4 year-old computer with the original installation of Windows 7 has not flinched once. Not a single "boing", "twang", "pop" or dropout. From what Scott has said I can push things much further with my settings but I am very content at this point because it is running great and I cannot hear any latency at all.

My latency settings for the UMC202HD interface at this time are:

USB streaming mode:   Low Latency (this can be moved one more notch)
VAC and UMC202HD Buffer size:  1024  (some have run this at 512 or even 256 but I have not gone that low)
VAC latency setting:   30ms  (Scott has indicated that 25ms should not be a problem but I have not tried that yet)

I would imagine that using DAW software and VST plugins would introduce a higher potential for more latency but simply using the USB interface is a very light burden for most Windows 7 and later machines. So far so good!

73,

Rob W1AEX

Selectable sideband reception for the SAM mode in OpenHPSDR

I often hear people knocking the OpenHPSDR software because of their assumption that it is "the same old PowerSDR from Flex". Nothing could be further from the truth. While the standard GUI looks similar to the old Flex versions of PowerSDR it is ALL NEW UNDERNEATH that familiar looking GUI. One example is the ability to use selectable sidebands with the synchronous detection mode on AM. Notice that there is no degradation of the recovered audio when listening to only one sideband even though you are listening to half the bandwidth. This is very different from grabbing the filter edge and dragging one sideband in. The 30 second video at the link below demonstrates how you can listen to a weak AM station that is adjacent to a much stronger station that is pushing into one sideband.

https://www.youtube.com/watch?v=mBHnJFsgsZk (https://www.youtube.com/watch?v=mBHnJFsgsZk)

The all new DSP and digital audio chain along with pre-distortion linearization for TX only scratches the surface of what OpenHPSDR is capable of. Incidentally, if you do not like the busy "old Flex" look of the GUI you can switch to the collapsed mode GUI which looks nothing like the Flex version of PowerSDR!

Rob W1AEX

I am jealous and can hardly wait until people like me can afford used Anans. I have been lobbying Flex for several years to include selectable-sideband sync detection in PowerSDR to no avail. Now it will never happen, of course, because 1) Flex's PowerSDR quit accommodating my SDR-1000 at version 2.5.3, and 2) Flex's PowerSDR is unlikely to be updated beyond 2.7.2 since all their time and effort is now being devoted to SmartSDR.

Selectable-sideband sync detection is even better than it appears to be because you are cancelling the interference from one sideband, but you are still listening to BOTH sidebands of the AM signal. This gives a 6 dB advantage over "dragging the filter edge over" to remove interference. It was also the method designed into the pioneering tube-type sync detectors built by W2CRR and W3DUQ and a few others. It can do this apparent magic because the Q detector recovers NONE of the AM audio, therefore adding or subtracting the output of the Q detector cancels only interference.

That is the magic of DSB -- and, right now, only Anan (and a few homebrewers) are taking advantage of it.

73,


Kevin, WB4AIO.

Kevin,

I really like this feature and use it frequently when running AM in areas of the band where a signal starts up in one our sidebands. Your description of what is going on with this reception mode is "spot on". In one of the ANAN discussion threads the developer of this and many other features in OpenHPSDR (Warren NR0V) offered an explanation of how it works:

...it is a phasing technique.  What this means is that you do not have to be centered on the received signal to take advantage of the sideband selection ... it picks out the correct sideband whether you're centered or not.  I've found this useful in a round-table with stations having vintage gear.  They are often a Khz or two apart in frequency (or is that a Kc or two).

Anyway, I have some vintage gear here too; so, I'm sensitive to the issue!

Another interesting feature specifically for AM reception as seen in the attached image is the "fade leveler" which I use quite a bit while doing AM broadcast DX-ing to overcome flutter. It works very nicely but can cause a very long recovery time if you use it in a QSO with a very strong station. You can also control the squelch tail length for AM if you wish to use the squelch. I do use that when I leave a receiver on 50.4 MHz or even 29.0 MHz to catch an opening now and then.

73,

Rob W1AEX

Very nice, Rob.

I am not sure what exactly the Fade Leveler does -- how is it different from normal AGC? Does it somehow try to compensate for the phase shifting inherent in the cacophony of mixed carriers on a typical AM broadcast channel? Or is it just a gain thing?

Is there a url where I can read more about the development of this detection system -- such as the one you quoted from?

One thing they ought to change, though: the sideband select for sync mode ought to be on the front panel, not in a menu. It's the sort of thing one might need to change rapidly if an interference situation suddenly develops.

Thanks and 73,

Kevin, WB4AIO.

Yeah Ralph, I got lucky and heard the squelch break on my 10 meter bandwatch receiver. It didn't last long though! You've definitely got good eyes young man!

Kevin, the attached PDF file written by Warren NR0V is somewhat dated in some areas but the section on page 4 regarding selectable sideband synchronous AM and the fade leveler are current. Warren's explanation from page 4 of how the Fade Leveler functions is pasted in below:

"For AM Demodulation & SAM Demodulation, the “Fade Leveler” function will often reduce
fading and improve the audio for AM. It operates by removing the fading carrier and replacing it
with a much more stable carrier. Note that if this function is used with the Automatic Notch
Filter, you may wish to select the “Post‐AGC” option for the ANF. Otherwise, the ANF will notch
out the carrier before the AGC and therefore the carrier will not have the intended quieting and
stabilizing effect."

Ignore the obsolete sections on ALC and also the section on noise blankers. There is now a look-ahead algorithm that makes it impossible to drive the ALC past 0 dB so you can drive the snot out of the audio and it will not distort or degrade the IMD. Also, there are now 3 noise blankers (2 different wideband noise blankers and a spectral noise blanker that was just introduced this week).

There's a fair amount of used ANAN hardware around Kevin as guys work their way up the hardware chain. If you are not already a member I would suggest joining the Apache Labs user group at the Yahoo forums as people list stuff there frequently.

https://groups.yahoo.com/neo/groups/apache-labs/info (https://groups.yahoo.com/neo/groups/apache-labs/info)

If you are interested, you can also download the user manuals for all the ANAN hardware at the Apache Labs download link below:

https://apache-labs.com/al-downloads/1007/ANAN-User-Guides.html (https://apache-labs.com/al-downloads/1007/ANAN-User-Guides.html)

73,

Rob W1AEX

   Some big reverberations in the Flex Power SDR 2.7.2 world are emerging as Darrin, KE9NS is wading through the source code and has made several interesting and useful enhancements for Flex 1500,3000,5000 owners. There seem to be several updates a week where the Powersdr.exe file is already compiled, and easily downloaded, and then switched out with the original file.

One caution is to backup or rename the original Powersdr.exe file. :-)

http://ke9ns.com/flexpage.html

Revision History:
http://ke9ns.com/flexpage.html#GPLREV

Attached the Water Fall Call sign. It is a little blurred, but that is my call as I print it...


Jim
Wd5JKO

That's great news Jim and it will definitely enhance the fun factor for the 1000/1500/3000/5000 owners beyond anything anyone might have expected! I love the analog meter!

73,

Rob W1AEX

Look at the last release that came in last night:

"02/10/16 N6: Fix: Increase TX Bandwidth on Flex1500 and Flex3000 to 10khz wide.
Fix: Improved Waterfall ID 24bit bitmap transmit. Automatically reduced the TX High filter down to 2.6khz during transmit, then back to its prior value. Still learning Bitmaps, and PCM and the conversion between them."

The bitmap waterfall of an owl worked perfect on my F3K. On AM the individual side band images are of course mirror images of each other...

Jim
Wd5JKO

Jim,

The bandwidth limitation for the 1500/3000 series has always been a sore point for a lot of Flex users. Those who use them on AM are going to be celebrating with that news!

Rob

   Rob, I tried things out last night set to 6 Khz max audio. Tuning around the Ghetto on 75m, I would have to decide on whether I would cover up 4 QSO's or 2 with my bandwidth selection.  :P  Actually the original Flex 4.5 Khz upper end is not too restrictive, especially since my ears don't go up like they used to.

   Looks like Darrin KE9NS has another update since I downloaded last night....

   I wonder what the Flex folks are thinking about this?

Jim
Wd5JKO

Maybe one of the reasons they just instituted a buy-back/trade-in program for all the old Flex SDR rigs to apply to a purchase of a Flex 6000 Series radio.

I would guess this will not work with the anan, but does anyone know of a way to print out a call sign on the waterfall with the anan, or will this actualy work. I just figure if I replace the file it would wipe out all the features of the openhpsdr that I like so much, and the simple little print out a callsign thing that I would probably never use on the air would not be worth it.  I think it would be neat to do a waterfall call sign atleast once though.

73
Brandon


hope to hear you on the air jim, I have not heard you on much like I used to.

  I was on 15m AM today trying out the Flex 3K with 6 khz +/- audio. Also sent a waterfall image on AM that was just "JKO | OKJ" to Robert W0VMC, and it came through!

Big weekend for Flex SW updates from KE9NS:

02/13/16 O6: ADD: Flex3000 Now has 192k Sample Rate (you can view around 170khz on the screen at 1 time), in addition to the 10khz wide TX (edit from JKO: 20Khz AM!)
02/13/16 O5: Fix: TX WaterID Now runs on its own background Thread (see video).Creates file when you change the Callsign text field.
02/12/16 O4: Fix: TX WaterID much faster to create image if running 96k or 192k Sample rates. Fix: Flex Audioplayer has a automatic resampler, but the code to make it work had some missing pieces, fixed the missing pieces, so now 48k waterfall resamples for 96k and 192k SR.
02/12/16 O3: Fix: TX WaterID labels: Creating->Transmit-Tx WaterID. Add Grayscale to database. Database name now: ke9ns1.dat
02/11/16 O2: ADD: Database to save mod settings: Callsign ID, Wide waterfall, etc.
02/11/16 O1: Dttsp compiled to SDK 8.1. and PowerSDR compiled under NET 4.5.2. PowerSDR.exe file slightly larger because Cdecl requires each function to have its own cleanup code. The Downside is that you must also copy over a "PowerSDR.exe.config" file becuase of the old FLEX1500USB.dll. NET 4.5 is supposed to be an improvement over the NET 3.5 PowerSDR was using.

Jim
Wd5JKO

Steady progress in PowerSDR. We can now monitor ourselves when on AM...

Release notes from Darrin Ke9NS:

http://ke9ns.com/flexpage.html


02/23/16 P5: Add: MON toggle between MONpr (Pre-Processed monitor) and MONps (Post-Processed monitor) for 3000 and 5000.

02/22/16 P4: Add: MON (pre-processed audio) to AM/FM for Flex1500 only in VAC mode though (not through the PHONES jack on the 1500).

02/20/16: P3: Add: MON (but pre-processed audio instead of post-prosessed) to AM/FM modes for Flex3000 and Flex5000.
Add: turn off DoScope() if your not actually using it to save cpu cycles

The MON is normally turned OFF for AM/FM modes. I enabled it for AM, but the MON output in the speakers, headphones, VAC is modulated AM (to the edge of the passband), this is because MON wants to use post processed audio. I will need to use pre-processed audio for AM/FM mode, so its not the audio you are transmitting, but at least the MON function works now.

02/18/16 P2: Add: Auto Waterfall Transmit Low level adjustment. Key the radio and Click "Auto Wtr Level" to set Waterfall for transmit input level.
Fix: Waterfall only, not displaying correctly due to addition of avgP, avgB previously. Auto Wtr Level turns off if you just in panadapter mode.

02/18/16 P1: Add: Auto Waterfall Low Level Adjustment. Just click the "Auto Wtr Level" button below the display area.

02/17/16 O9: Fix: Found mistake in Source code when compiled under VS2015 caused the check for atu.dll to fail, so Flex3000 units were using OLD ANT Tuning algorithm. Also Dttsp.dll now is updated to current 2015 v140 toolset, hopefully no issues. I embeded vc_redist_x86 into the DttSP.dll.

02/16/16: Figured out how to compile DttSP.dll under v140 platform toolset. Dumpbin showed v140 requires vc_redist.x86 since DttSP is a 32bit C application. Recompile DttSP.dll under C code generate runtime /MT (instead of /MD) will include all required DLL's

02/15/16 O8: Fix: Add toolTips to TXWaterID and Callsign box. Save the AvgP or AvgB settings in database.
Right Click on Callsign Box to open up Folder where you put your own bitmap files to send to the waterfall.
Right Click on the REC button to open up Folder where you will find SDRQuickAudio.wav files from your REC / PLAY use
Right Click on the your current skin (Setup->Appearance->General->Skins->current skin) to open the Folder to the SKINS
.
02/14/16 O7: Fix: Prevent (if you accidently hit the TX Waterfall ID with the Radio OFF) keying the Transmitter when the Radio is OFF (sitting idle)

Is there zero latency with the P5 pre-processed audio monitor?  In other words, you hear no delay between talking in the mic and hearing yourself in the headphones?

Thanks & 73,
Barry N1EU

Barry,

   I was playing with that last night using P5 release. With my F3K, for AM MON, it is pre-processed, and there is no delay that I can tell. For SSB, the MON button has the option of pre or post processing. I can hear some delay on post processing, but that depends on the sample rate and buffer size.

   I was experimenting with my AM saved profile settings on SSB Mon where I can tell a lot from pre/post processing. Then I can save it for AM.

I just noticed P6 is out..

Jim
Wd5JKO

Many more enhancements to PowerSdr 2.7.2 since my last post.

All the SW broadcast bands are added under the 'GEN" button. Also many improvements to the audio recording and playback. This has always been a problem for me with AM playback since the carrier level would come on too strong. Lowering the Wave Gain would fix the carrier pumping, but would also drop the modulation percentage. With the Q3 release, these issues seem much better.

http://ke9ns.com/flexpage.html
http://ke9ns.com/flexpage.html#GPLREV

Jim
Wd5JKO

Power SDR has seen steady progress with about 5 updates a week thanks to Darrin, KE9NS. The latest stuff has to do with SWL and DX spotters indicated on the pan adapter. Do a cntrl right click on the DX spot, and it takes you to the fellows QRZ page. Do the same with SWL spots and it takes you to Google search with the search field filled in. Then as of today we have a world map background along with the options of adding gray line and sun positions that track over time.

I attach some pictures of both DX and SWL spots. The center picture shows a big Ham AM signal on 7290...

Some DX Spotter sources:

spider.ham-radio-deluxe.com   port 8000 (must have an account)
k1rfi.com    port 7300
ve7cc.net    port 23

Video highlighting S5 by Darrin, KE9NS:
https://www.youtube.com/embed/3InG8QgMTIY

Jim
Wd5JKO

There have been many updates since my last post. Darrin KE9NS has been very busy over the summer. One area where there have been significant advancements has been towards the short wave broadcast SWLer.

I include a screen shot of the T9 release. Notice the Desktop Map with active grayline, and position of the Sun with the Solar Flux index.

The screen shot is from my Flex 3000.

http://www.ke9ns.com/flexpage.html

Jim
Wd5JKO

Jim:
From your attached picture, what's the lower right meter used for in your Flex-3000?

Pete,

  It is a duplicate of the main transmit meter. I like to use the original meter to look at Forward Power, and the 2nd meter to look at one of the audio levels such as EQ.

For those with a F5K with 2nd receiver, the 2nd meter does what it always did. For those of us with a F1.5K or F3k, this 2nd meter function is a nice addition.

Jim
Wd5JKO

I forgot you can bring up the second meter in the transmit profile. I just pulled down T9 (I was running T8) and installed it and diddled with the settings. Works fine. Weeks ago I upgraded the shack PC to Win 10, 64 bit, and added 8 Gig of memory. The machine was running Vista 32 bit with only 3 Gigs of memory and CPU usage was always high. I still would like to find a program that would shut down some processes on the "new" machine that I don't need when I'm running the Flex 5000 and some of the digital programs. I use to run GBOOST on the old machine which worked great but evidently the server(s) that activated the software no longer are functional.

Pete,

   The use of Win 10 to run radios has been largely successful. Darrin, Ke9NS has a section on his F5K page on Win10, and how to tweak it. There are lots of issues with Win10 though after some of the MS updates and how they impact the SSDR users.

   The T9 PowerSDR up till a few days ago used a Microsoft installer. Therefore to upgrade further you need to uninstall from Control Panel like most any Windows program. Now moving on from here, he has went to a different installer that will not be seen in Control Panel programs list. This is a little confusing.

   Here is a recent post from Darrin showing the current features of his T9 revision of PowerSDR:

https://community.flexradio.com/flexradio/topics/powersdr-2-7-2-ke9ns-revision-t9-available-for-download

Jim
Wd5JKO

The link below leads to a setup guide for attaining audio level settings that are optimal when adjusting each gain stage in the transmit chain of the PowerSDR mRX PS software. The short story is that while the GUI interface resembles the Flex version of PowerSDR the reality is that the entire transmit audio chain from front-to-back is completely different. The bottom line is that it is absolutely critical to make sure that you are regularly reaching 0dB on voice peaks while transmitting and observing the ALC meter.

This will assure that the Pure Signal algorithm samples your RF signal frequently to allow the adaptive pre-distortion protocol to apply an optimal correction to your output signal. It is almost a worry-free setup as the look-ahead algorithms at the LEVELER and ALC points in the transmit chain of the software make it absolutely impossible to drive the transmitter into clipping. It doesn't matter if your setup is simply a microphone plugged into the front panel, or an audio rack plugged into the rear panel DB25 line level input, or even a VAC setup using DAW audio processing software, getting it right is simple as long as your MIC/VAC, EQ, and LEVELER are adjusted correctly.

Hope this makes it simpler for all the guys who are just starting out!

73,

Rob W1AEX  

http://www.w1aex.com/anantxgain/anantxgain.html (http://www.w1aex.com/anantxgain/anantxgain.html)

A couple of new items for the ANAN platform of SDR rigs:

New firmware release for the Hermes based ANAN-100 rigs (Hermes_v3.2.rbf) available at this link:  

https://github.com/TAPR/OpenHPSDR-Firmware/releases (https://github.com/TAPR/OpenHPSDR-Firmware/releases)

New OpenHPSDR mRX PS release for all platforms. This incorporates the new Pure Signal 2.0 pre-distortion protocol which is far more robust in its capability to correct problematic linear amplifiers that exhibit memory effects. Additionally, the Pure Signal 2.0 protocol can be enabled via the front panel GUI and will remain toggled on persistently each time OpenHPSDR mRX PS is started up as long as the PS-A button (seen in the upper left of the image below) remains engaged.

https://github.com/TAPR/OpenHPSDR-PowerSDR/releases (https://github.com/TAPR/OpenHPSDR-PowerSDR/releases)

New beta release of CuSDR (version 3.3.0 QT5) from Herman. There is no installation for this program, just download the zip file, extract the files to any folder of your choosing and run it from there. I found it necessary to let the program run with admin privileges otherwise I received an error message (The program has stopped working) when it was started. This version does not yet have the WDSP protocol installed, but it looks beautiful, runs smoothly, and is very stable. I was able to open up 5 receivers simultaneously (seen in the second image below) in addition to running the wideband RX display of the spectrum from VLF through 64 MHz.

https://github.com/hvh/cusdr3/files/862159/cusdr3.zip (https://github.com/hvh/cusdr3/files/862159/cusdr3.zip)

I made a YouTube video of CuSDR v3.3.0 (QT5.4.0) as I was listening to an AM conversation on 75 meters yesterday. The fidelity of CuSDR is very nice and rivals OpenHPSDR mRX PS when tuning the AM broadcast band.

https://www.youtube.com/watch?v=sYIkvBrSITU (https://www.youtube.com/watch?v=sYIkvBrSITU)

Lots of good stuff to play with!

Rob W1AEX

Thanks to the efforts of Warren - NR0V, Doug - W5WC, and Chris - W2PA the user base for OpenHPSDR mRX PS is enjoying a major software upgrade with the release of version 3.4.1 that is now publicly available. Gone are the days when a new release meant you would have to reset your database and then sort through the menus to set everything up again as well as plunging through the tedious task of re-creating your transmit profiles and filter sets. The new v3.4.1 release will import any database you throw at it and migrate everything into a new database that is compatible. To test how smart the new database migration tool is, I went back to databases that I used 3 years ago and it migrated them flawlessly. My biggest surprise was when I went to an old database from my Flex 5000 and it migrated that without a hitch!

Additionally, the version 3.4.1 release contains the long-awaited CFC Audio Tools implementation which offers PRE-EQ, CFC (10 Band Continuous Frequency Compression), POST EQ, Phase Rotator, and an adjustable soft-limiting ALC Max Gain setting. These new audio tools can be used in conjunction with the adjustable soft-limiting leveler, conventional wide-band compressor, and the CESSB option. Of course all the audio options can be further enhanced with the adaptive pre-distortion linearization protocol that reduces the transmit THD from the nominal 2.0 % to 0.2%.

If that was not enough to play with, version 3.4.1 also adds the ability to transmit AM with one sideband, your choice whether it be the upper or lower sideband.

For those users who are clinging to an old version of OpenHPSDR mRX PS there is absolutely no reason not to upgrade to this one! The developers really hit a home run this time!

73,

Rob W1AEX

Note the setup information in the videos below is applicable to AM and SSB modes:

Quick Setup Guide for the CFC Audio Tools:    https://www.youtube.com/watch?v=l5JmDAaDBVo (https://www.youtube.com/watch?v=l5JmDAaDBVo)

Using the new CFC Comp and ALC Comp metering to adjust CFC Pre Comp and Post EQ levels:    https://www.youtube.com/watch?v=o73aAc9oWnw (https://www.youtube.com/watch?v=o73aAc9oWnw)

Adjusting the OpenHPSDR mRX PS Phase Rotator:   https://www.youtube.com/watch?v=NM2x2tk0UbY (https://www.youtube.com/watch?v=NM2x2tk0UbY)

Over the past two weeks there has been quite a lot progress made with the release of new protocol 2 firmware for the Apache Labs ANAN radios. The older protocol 1 firmware that is used to run OpenHPSDR mRX PS and other programs such as the Zeus Radio software and CuSDR is limited to 100 Mbps through the ethernet port. This bandwidth cap limits the number of possible RX paths and the amount of data exchanged between the hardware and the computer software that is being used. This is not a huge problem when you are running smaller sampling rates such as 192kHz and one or two receivers along with the predistortion protocol (Pure Signal), but it is a problem if you decide to run higher sampling rates plus a second receiver along with Pure Signal which requires an RX path of its own. The new protocol 2 firmware runs at gigabit speeds and can handle sampling rates as high as 1536kHz in RX1 and RX2 along with Pure Signal with lots of headroom left over.

It is really easy to move your ANAN to the protocol 2 firmware, and if you wish, it takes less than a minute to move it back to protocol 1. At this time many users are moving back and forth between the two protocols almost daily to test out new software releases, so as long as you are comfortable using the HPSDRProgrammer utility (used for flashing protocol 1 firmware or for flashing from protocol 1 to protocol 2) and the HPSDRBootloader (can be used for flashing any protocol 1 version to another protocol 1 version, or to move from one protocol 2 firmware version to another protocol 2 version, or for flashing from protocol 2 back to protocol 1) which requires installing the WinPCAP libraries and also moving the bootloader switch in the hardware, you should be good to go. There is also a very nice P2 web programmer which works beautifully and does not require using the bootloader switch or the installation of the WinPCAP libraries. Everything you need to know about flashing the firmware can be found at this link:  

https://apache-labs.com/community/viewforum.php?f=18 (https://apache-labs.com/community/viewforum.php?f=18)

When you flash your ANAN to the protocol 2 firmware the original OpenHPSDR mRX PS software will not run with your ANAN hardware, so you will need to move to the Thetis software package or Simon Browns SDR Console. Both of these packages are completely independent of each other and do not interfere with each others settings or your original settings in OpenHPSDR mRX PS. So, you can feel free to experiment without disrupting anything in the other software installations.

The trickiest part of the new protocol 2 architecture is getting the new firmware to play well with the FPGA in every piece of hardware that is out there. After a lot of effort on the part of the volunteers who handle the firmware development a lot of progress has been made. Using the last firmware release (January 5th) my ANAN 200D is able to run both Thetis and SDR Console without any anomalies with TX and RX but as protocol 2 is still in beta that is not the case with everyone's hardware. So if you want a little adventure, you might want to give it a shot. If you don't flash you can't play!

Rob W1AEX

The three screenshots: 1) Thetis in collapsed mode listening in the AM Ghetto  2) SDR Console in QSO with N1BCG  3) Thetis at 1536 sampling rate on the AM BCB

Been a while, but this post needs an update.

PowerSDR for Flex Legacy users, there has been a ton of updates. In fact Darrin, KE9NS is on a tear so far during this Pandemic.

Take a look here, lots of new stuff, videos, etc.

https://ke9ns.com/flexpage.html#home

Jim
Wd5JKO

For those using the ANAN platform to get their AM fix be advised that PowerSDR mRX PS has reached EOL and there will be no further development for that software platform. All further development will be with the Thetis/Andromeda platform which has the ability to auto-detect whether you have protocol 1 or protocol 2 firmware installed in your hardware. So... for those who have resisted moving to protocol 2 you can enjoy all the new features in Thetis and keep your hardware at protocol 1. Additionally, with Thetis you can install either the 32-bit or the 64-bit version or both if you like.

There are many new features installed in Thetis that are not in PowerSDR mRX PS including the display option to run Direct X (reduces the CPU utilization by offloading the panadapter/waterfall rendering to the video card's GPU), updates to the REC/PLAY feature with auto VAC bypass and CFC auto-disable during playback, addition of a status bar at the bottom of the GUI for on-the-fly RX and TX antenna switching along with an integrated ID timer. Additionally, the KE9NS spotter utility is integrated into Thetis. You also have the option to run Thetis with the onscreen Andromeda control panels. This is especially useful for those with a 4k monitor and lots of screen real estate or for those who have multiple monitors as the undocked Andromeda control panels can be put anywhere on the screen or dropped onto other monitors if you wish. There are many other refinements under the hood as well to assure smooth running.

For those who still want to cling to their PowerSDR mRX PS software you can leave your current installation in place and install Thetis anyway because the programs are completely separate and do not install into the same folders. You can also export your TX profiles from PowerSDR mRX PS and then directly import the profiles into Thetis and they will operate fine with all your carefully tailored audio setups. You can still run either program whenever you want but not simultaneously. The software is updated regularly and it keeps getting better and better!

73,  Rob W1AEX

Will this support other radios using protocol 1?

IE, the Hermes Lite?


That would be awesome if it did!!!


--Shane
KD6VXI

Shane,

According to the Apache Labs forum, it supports everything except for the old HPSDR Atlas backplane models. If you have a Hermes-Lite it should be good to go with your protocol 1 firmware.

Rob W1AEX

https://apache-labs.com/community/viewtopic.php?f=9&t=3557 (https://apache-labs.com/community/viewtopic.php?f=9&t=3557)