Something of interest to smug Flex operators on AM

[W1AEX]

Flex has resolved this issue with the 2.2.3 (final) release of PowerSDR that came out today:  

DE584 AM AGC does not take carrier into account

With the new version, you can crank the AGC-T control to the max and the AGC will handle it like it should. No more "rushing compressed sound" with stations of different strength. The first station in the mp3 file (NF1A) was about S-7  to S-8 and Tim was floating up near 30dB over. The AGC-T control for this recording was pushed all the way to the right (120). Notice how the AGC now responds correctly with the new code they have provided. Both signals sound very similar in loudness in spite of the large difference in signal strength, even in the presence of the static crashes on 160 meters this evening. It's a huge improvement for AM reception with PowerSDR.

Enjoy!

73,

Rob W1AEX

[K1JJ]

Rob, you're getting that whole system so well optimized, it's scary.  

I'm feeling so left behind and inadequate.... [sigh]

The AEX-FLEX!

T

[W1AEX]

Inadequate? Mr. Vu? Not likely!

You should jump in on 1885 with us. Conditions are pretty good in spite of the static crashes. There's the usual collection of miscreants holding court.

The info below from the release notes might interest you:

Version 2.2.3: Enhanced Signal Clarity (ESC) is now officially supported in PowerSDR. ESC with the FLEX-5000 and an RX2 is a unique synchronous dual receiver system that allows for the enhancement or nulling of signals in RX1 by manipulating the phase and magnitude from the second receiver to provide a beam steering or null forming functionality in software.

:O)

[K1JJ]

Version 2.2.3: Enhanced Signal Clarity (ESC) is now officially supported in PowerSDR. ESC with the FLEX-5000 and an RX2 is a unique synchronous dual receiver system that allows for the enhancement or nulling of signals in RX1 by manipulating the phase and magnitude from the second receiver to provide a beam steering or null forming functionality in software.

:O)

So they made up their "own" name  -  Enhanced Signal Clarabell-ity - fancy marketing ..  

Yep, that dual receiver null steering has been working in the Mercury receivers via W5SO? PSDR for some time now. I still need to get a second one here. Frank is actually talking about three RX's now.  

Haven't been on much lately, Rob.   I should get on soon. Starting a new biz and had to pass some difficult licensing tests, etc. I'm getting too old for this testing stuff...

T

[Pete, WA2CWA]

I was down on 75 meters around the same time playing with the new version. Enabled "ANF", when receiving in the AM mode, still increases the audio output to the speakers. Still not sure what the purpose is.

[WA1GFZ]

Yup,
just rebuilt my HPSDR with bigger 5 volt supply to support a third Mercury. Beam steering is very cool. Getting ready to put up a 4 square. A 4 square into three or 4 mercury receivers would be quite cool. K5SO working on new software that will take into acount antenna spacing. A 4 square with variable delay looks interesting in simulation. Very smug

[WA3VJB]

The first station in the mp3 file (NF1A) was about S-7  to S-8 and Tim was floating up near 30dB over.
Both signals sound very similar in loudness in spite of the large difference in signal strength,
even in the presence of the static crashes on 160 meters this evening.

It's a huge improvement for AM reception with PowerSDR.

Rob that's an impressive recording, knowing the signal disparity and hearing the static crashes besides.

I hope you're behind some of the push to get them to address this issue, and I also hope they'll see how the AM community is enjoying their radios.

[W1AEX]

Rob that's an impressive recording, knowing the signal disparity and hearing the static crashes besides.

I hope you're behind some of the push to get them to address this issue, and I also hope they'll see how the AM community is enjoying their radios.

Hi Paul,

I can't claim to have been any part of the solution to this issue. All I did was file a report to the bug list along with quite a few others. In fact, I believe that Frank WA3JBT was one of the earliest to bring this to their attention. Once the Flex guys saw what was happening it got assigned to one of their software guys for correction. Flex seems genuinely interested in providing whatever enhancements they can to every operating mode, and they are very interested in the AM community. When they re-wrote the ALC code last spring, they watched very closely to make sure it didn't have any regressive effects on the TX performance of AM. They went out of their way to grab a few of us who use AM to test the re-write before it was released. I have always been impressed with their willingness to listen to their customers.

So, from what I can see, it looks like they really hit the target with the 2.2.3 release. Today, I loaded half a dozen AM broadcast stations of differing strengths into memory and then stepped through them with the AGC-T cranked all the way to the right. The amplitude of the stations remained remarkably even, and there was no evidence of pumping or compression on the strongest stations. This morning on 40 meters I chatted with a few guys, and recorded about a minute of Frank WA3JBT as he rolled in and out of two deep selective fades. Again, the amplitude of his audio was remarkably steady. In the past, the audio levels would have been all over the place. I think anyone who plays with AM is going to like it a lot.

73,

Rob

Frank - WA3JBT on 40 Meter AM:    http://www.youtube.com/watch?v=wSKToJZV9vg

[flintstone mop]

ok I installed 2.2.3 Smug software and when I want to listen to something out of the Ham bands, I get a warning that the TX frequency is not allowed and shuts down the radio/hardware.
How do I get around that one??? I gave up on a version of Power SDR because of that.
I don't need no software telling me what I can tune to and that my TX audio filter is set too wide....6KC is too wide???
Tell me some secrets
Thanks
Fred

[flintstone mop]

ok I installed 2.2.3 Smug software and when I want to listen to something out of the Ham bands, I get a warning that the TX frequency is not allowed and shuts down the radio/hardware.
How do I get around that one??? I gave up on a version of Power SDR because of that.
I don't need no software telling me what I can tune to and that my TX audio filter is set too wide....6KC is too wide???
Tell me some secrets
Thanks
Fred

ooops I had to assign the port I'm using to communicate with the hardware.....the fun begins........setup of vac and comm o comm etc...but the hardware.......is very happy now.....more later.........

[Steve - K4HX]

Any intermod tests, especially for mod freqs below 100 Hz?

Rob that's an impressive recording, knowing the signal disparity and hearing the static crashes besides.

I hope you're behind some of the push to get them to address this issue, and I also hope they'll see how the AM community is enjoying their radios.

Hi Paul,

I can't claim to have been any part of the solution to this issue. All I did was file a report to the bug list along with quite a few others. In fact, I believe that Frank WA3JBT was one of the earliest to bring this to their attention. Once the Flex guys saw what was happening it got assigned to one of their software guys for correction. Flex seems genuinely interested in providing whatever enhancements they can to every operating mode, and they are very interested in the AM community. When they re-wrote the ALC code last spring, they watched very closely to make sure it didn't have any regressive effects on the TX performance of AM. They went out of their way to grab a few of us who use AM to test the re-write before it was released. I have always been impressed with their willingness to listen to their customers.

So, from what I can see, it looks like they really hit the target with the 2.2.3 release. Today, I loaded half a dozen AM broadcast stations of differing strengths into memory and then stepped through them with the AGC-T cranked all the way to the right. The amplitude of the stations remained remarkably even, and there was no evidence of pumping or compression on the strongest stations. This morning on 40 meters I chatted with a few guys, and recorded about a minute of Frank WA3JBT as he rolled in and out of two deep selective fades. Again, the amplitude of his audio was remarkably steady. In the past, the audio levels would have been all over the place. I think anyone who plays with AM is going to like it a lot.

73,

Rob

Frank - WA3JBT on 40 Meter AM:    http://www.youtube.com/watch?v=wSKToJZV9vg

[KA3ZLR]

Good Day, Smuggerz  

 I'm waiting on one of those Flea Bags to go Bang then we'll see what the actual worth of those
Great Audio Generators are, is , whatever...  

Can You say SMT..?  LOL....

73
Jack
KA3ZLR
 

[W1AEX]

Any intermod tests, especially for mod freqs below 100 Hz?

During RX or with TX audio Steve? As someone with no formal technical training I won't pretend to even know what you are asking!

:O)

[KA3ZLR]

Can ya Hear N.A.T.O.    over...if ya can it's a problem....

73
Jack
KA3ZLR

[W1AEX]

I was down on 75 meters around the same time playing with the new version. Enabled "ANF", when receiving in the AM mode, still increases the audio output to the speakers. Still not sure what the purpose is.

Pete,

I have noticed this as well. When tuned to an AM BCB station that is S-9, when the ANF is engaged, the S-meter drops down slightly and the audio rises by about 25% (best guess by ear). My own conclusion is that the ANF reduces the carrier strength and the AGC responds by increasing gain. I'm not sure if that's what is really happening, but it seems logical.

Rob

[flintstone mop]

Any intermod tests, especially for mod freqs below 100 Hz?

During RX or with TX audio Steve? As someone with no formal technical training I won't pretend to even know what you are asking!

:O)

Judging by the time stamp that Steve posted, I think he was very tired. I'm a little baffled or getting Smugger wondering myself about intermod below 100hz.  Re-checking the setups for Freq Cal, Image rejection, and Receive RF level Cal. And hopefully not as much dummy load testing for the audio setup of the ALC,etc etc...A lot of 'vitural knobs' to tweek.

[KA3ZLR]

I think he's talken about Receive inter mod...but I could be wrong...an maybe not...


73
Jack
KA3ZLR

[flintstone mop]

The ANF seems to reduce noise and narrows the audio response. Sounds like the audio goes to space shuttle mode/ telephone quality. I was tuned into a BC station and there was another station close by skipping in with its IBOC sidebands.
Other than the usual setups I like the better AGC/ALC, the TX AM audio looks like it will schwang the munkey a little more. I'll call it the built in processing within the Power SDR. ALC action the Leveler etc etc. I had to input more audio into the sound card and the wave form on the 'scope is rockin'!!!
Fred

[Pete, WA2CWA]

Pete,

I have noticed this as well. When tuned to an AM BCB station that is S-9, when the ANF is engaged, the S-meter drops down slightly and the audio rises by about 25% (best guess by ear). My own conclusion is that the ANF reduces the carrier strength and the AGC responds by increasing gain. I'm not sure if that's what is really happening, but it seems logical.

Rob

I haven't seen any S-meter movement up or down when I engage or disengage the ANF.

[Steve - K4HX]

Detect an AM signal, modulated with two-tones. Measure the intermodulation between the two at the detected output. Take a look at W1VD's harmonic distortion measurements on receivers. Most get real ugly at high modulation percentages and low modulating frequencies. And that's just THD. The response time of many AGC systems is too slow to effectively deal with low modulating frequencies. Essentially, the AGC begins  to react to the modulation instead of the carrier level.

Any intermod tests, especially for mod freqs below 100 Hz?

During RX or with TX audio Steve? As someone with no formal technical training I won't pretend to even know what you are asking!

:O)

[flintstone mop]

Good point Steve..........
There is the same anomaly with audio compressors.

[W1AEX]

Detect an AM signal, modulated with two-tones. Measure the intermodulation between the two at the detected output. Take a look at W1VD's harmonic distortion measurements on receivers. Most get real ugly at high modulation percentages and low modulating frequencies. And that's just THD. The response time of many AGC systems is too slow to effectively deal with low modulating frequencies. Essentially, the AGC begins  to react to the modulation instead of the carrier level.

Ahhhh. As my daughter's talking Barbie used to say, "Math is hard!" I will leave all that good stuff to Jay! I'm pretty sure Jay plays around with PowerSDR so perhaps he could be convinced to give the new version a look-see since it behaves very differently from earlier versions. Steve QIX was able to run the new version with his softrock, and I think Jay also uses it with a softrock. I only know that I like the big wurlitzer jukebox sound that it produces while listening to the AM or SAM modes!

Rob 

[Steve - K4HX]

You got it Fred. Both are basically single channel, wide band, feedback control systems.

Good point Steve..........
There is the same anomaly with audio compressors.