sources for panadapters, designs, kits, or pre-made.

[Opcom]

Are there any kits or suppliers for panadapters?

Like others, I have a few oldies and the like, but I would enjoy finding a kit or box that would take an I.F. in (from the mixer of first detector), and either take in a control voltage (sawtooth etc) or generate its own, and put out a sawtooth or sync pulse along with a swept spectrum. I would prefer to use an external XY display and would consider doing the CRT part myself.

I would not mind trying to build one from oldie tube parts, but the RF transformers are not very common any more. The mini-circuits catalog gives me ideas for a modern SS version that could be done in hardware (no evil software or fimware or PICs, etc).

I do not want to buy a radio with a built in one. I already have good radios. I would like to have something that is simple discrete parts, not requiring any kind of 'firmware', postage-stamp ICs, etc, unless it happens to be an inexpensive device that can be used with my existing shack computer, in which case I would consider it.

In the end, a kit or product would meet my needs best, and I would like to see any recent schematics.

Any pointers to suppliers or hardware are very much appreciated.

Thank you,

[KF1Z]

I don't know what you're looking for as far as bandwidth...

But some have found solice in the Softrock40

The kit is under $20... (around $15 i think now)

You can take the IF from your existing radio.. feed it into the softrock...
And then to the soundcard of your 'puter...

You can use it just as a 48khz wide panadapter... or delve into the world of software defined RX.

That's probably your best cheap bet...

The board is about 1 1/2" square... has only 10 Surface mount parts, the rest are discrete components.

http://groups.yahoo.com/group/softrock40/


My SRD Rx  gives me a 50Mhz wide display... (complete reciever.)
But for the price of it, you can buy  70 softrocks.. and it's not a kit.

[WA1GFZ]

don't waste your time. I've built a number of homebrew units driven by the scope trace. Junk at best. get a softrock and calibrate it using flex software and have a real tool.

[WBear2GCR]

You want the Soft Rock Lite 6.2 kit.
You'll need to specify the IF freq before ordering.
It was $12 inc shipping.

BUT you will need a computer with a soundcard to make it work.
The onboard soundcard will work but you'll want a 192khz or 96khz if you want to see more band, since you get 1/2 of that sample rate as your bandwidth - although someone else seemed to say you get the full bandwidth, mine isn't built yet so I dunno. Stock 48khz soundcards and you will get either 24khz or 48khz of band view depending on who is correct about that bit.

But 96khz soundcards are cheap if you need an external one, and many newer machines have 96khz build in... fyi...

                  _-_-

[kf6pqt]

Tony Parks, the gentleman the kits up the softrocks had initially retired the SoftRock v6.2 Lite receiver, which is the ideal (ie, simpler) version for a simple receiver. Fortunately he was convinced to do yet one more run of this design, so I just this past week received the one I ordered with a 455 kc center frequency, just for "panadapter" service.  I'd built another previously that was for the 7.040 40m cw area, and its a pretty amazing receiver.

For the $12 this thing will cost you, you should get over to:

http://www.softrockradio.org/SoftRock

Order one from Tony (paypal) and then join the previously mentioed yahoo group for any build and operation support.

I also have yet to build a more sophisticated version, its a receiver and QRP transmitter that will do both 80 and 40 meters.

Unfortunately I work with computers all day, so in my free time I like to stay away from them, so the one I've already built hasn't seen much use.

73,
Jason kf6pqt

[Rob K2CU]

An SDR converter/detector is probably the easiest way to do this as long as you have a PC to use and understand the limitations.

Remember that you will need to pick off the IF signal prior to any bandwidth narrowing filters or multistage IF strip. IF you look at IF output, you will only see a few KHz...the IF bandwidth.  the Softrock is sensitive enough for early on low level signals, but you will need to buffer the IF before inputting (50 Ohms) to Soft rock or other SDR converters. Much will depend on what radio you are using for the front end. Vintage tube radios tend to be pretty wide prior to IF stages, a plus, but you have high DC voltages to block with a coupling cap and higher impedances that can be screwed up due to mismatch. You would need some sort of FET type buffer/source follower. IF it is a newer solid state radio, you may have a roofing filter that could limit your bandwidth.  But, newer solid state radios usually have lower impedances 1000 to 50 ohms or so and easier to pick off a signal. A lot will depend on the architecture of the radio. Newer rigs tend to up convert before the roofing filter which may be at 40 to 70 MHz depending on manufacturer. These are probably beyond the Softrock range as an IF detector. This also means pulling your radio's pants down and sticcking your fingers in to the guts. why risk screwing things up?

I have experimented with using the Norcal FCC1/2 combination as the L.O. source for a Tayloe detector (like the Softrock). The Norcal unit will go to 20 MHZ output which basically results in a detector range of up to 5 MHz.  I connect it right up to the antenna and can look at any 80 Khz wide section of anywhere from the AM BC band to 5 MHZ. You just dial in a frequency that is four times the desired center frequency. On those bands it is sensitive enough so that antenna noise dominates the noise floor. I have used it with PowerSDR as that provides easy means for correcting for I and Q signals to null images. Works great!  I can use it alongside any receiver so that I don't have to risk screwing up any of the radios in the shack. No need to. I just T connect the inputs. Sure there is some loss, but at these freqs who cares. When combined with SDR software, you actually have a second receiver to boot! Just make sure it is on the receiver side on any T/R relay!


The FCC 2 kit does require special skills at surface mount construction and the DDS chip is a tiny bugger. From Norcals site: "You can have the SMT components installed by Kit Builders. Send Mike, WA6OUW, an email at wa6ouw@aol.com for further information."

So, I think the best solution, unless you want to try and fabircate an old style vacuum tube CRT combination panoramic adapter is to put together a combination of FCC1/2 and an SDR converter.  I have not yet tried using the Tayloe in an undersampling mode at higher frequencies than my FCC L.O. would work. That would require an input high pass filter. I am guessing that an L.O. tripler would be an easier way to get use at 40, 30, and/or 20 meters.

[kf6pqt]

That tayloe detector sounds pretty darn interesting!


I've built the fcc-1&2 combo... let me tell you that soldering that tiny DDS chip is a piece of cake if you use the solder-paste and hot air method.

Solder paste is 5 bucks plus shipping, and the mini-heat gun was like $14 from the crafty store.

Check this out... Myself and others have determined that you can totally skip the hot-plate pre-heating step:

http://www.zianet.com/erg/SMT_Soldering.html

73, Jason kf6pqt

[WBear2GCR]

Sorry, "whiteman speakum strange language"!

Could you please provide a link(s) to the Norcal and Tayloe?

What are these things? Who sells them? What sort of prices?

Interesting sounding...

    _-_-bear

[Opcom]

The softrock is interesting but would require a new computer and some mods.

Otherwise to use something like that with a scope it seems like a change of oscillator (4*I.F.?) and input filter would do. It seems that if the oscillator could sweep a range of perhaps 405 to 505 KC, and a low pass audio filter followed by a detector was placed at the output, it could do the job of scaning an I.F. and providing a linear output for a scope vertical deflection while covering a 455KC I.F. No messy PC required. Or maybe I do not understand how it works.

In case of the unit being use as intended, I am unsure of what the I and Q outputs are for, unless it is for the software to recognize and maybe get the sense of the spectral position or polarity correct.

[KF1Z]

Sorry, "whiteman speakum strange language"!

Could you please provide a link(s) to the Norcal and Tayloe?

What are these things? Who sells them? What sort of prices?

Interesting sounding...

    _-_-bear

The "norcal"  FCC1   is a frequency counter.... when you add fcc2 to it... you have a frequency counter, AND a DDS vfo.

Northern California    QRP club

http://www.norcalqrp.org/

[KF1Z]

The softrock is interesting but would require a new computer and some mods.


In case of the unit being use as intended, I am unsure of what the I and Q outputs are for, unless it is for the software to recognize and maybe get the sense of the spectral position or polarity correct.

Doesn't require a "super computer".... just any computer, with a soundcard.

NO mods would be needed....  lots of people using it for exactly your purpose.



The I/Q goes to the left, and right channel inputs to your soundcard.... the software takes it from there.

(I   is  "in phase"    Q   is the Quadrature  phase...   (90deg.))

[Rob K2CU]

The idea behind a panadapter is to have a mini spectrum analyzer that would display graphically, as in an oscilloscope display, the actvitiy in and around your tuned to frequency. This allows you to see if there are other signals on the band near you, as well as determining if that interference you hear is on the upper side, lower side, or both so you can deal with it. Generally you might like to see 20Khz to 30KHz or more, on both sides. 

That said, you can see the little value of seeing what is in your receiver's IF passband ubnless you are doing PSK-31 or some such. If you are tuned to 3885 KHz, for example, you might like to "see" a display window that shows you what is in the neighborhood from say, 3855 KHz to 3915 KHz. The old analog type of units might tap off the 455KHz IF at the output of the mixer, but before the narrow band IF filters. It might work as follows: The tapped off IF would be fed through a wideband IF amp and then to a separate mixer whose LO is a sweep oscillator. SInce you want to detect signals from 425 KHz to 485 KHz, the Sweep oscillator would go from, say, 475 KHz to 535 KHz for a second IF output of 50 KHz. You could then amplify and detect the 50 KHz, maybe with a Log amplifier.  The sweep oscillators ramp voltage, the Log amp output, and a blanking signal then go to an oscilloscope for display. Blah, Blah, Blah.....

I don't see how this is any less complex or costly than a cheap laptop and some simple circuits. It also requires a lot of circuitry to be built. You also have trade offs between the sweep rate and second IF bandwidth.

The Tayloe detector, Soft rock SDR kits, and any other PC soundcard based SDR radios all use the I and Q outputs with the stereo inputs of the sound card. Essentially, this whole shebang works in the inverse of a phasing type SSB generator. They are direct conversion receivers. The reason for the I and Q signals is to cancel out the image. In a simple analog direct conversion receiver, you feed the two signals into an audio phase shift network and either sum the two outputs or subtract them for either upper or lower sideband. IN the analog world, this is a bit trickey to build and have accurate phase shift over the entire audio passband. The PC DSP software makes it a snap.  Most of the programs provide a means to make trim adjustemnts of Phase and amplitude betwen the two inputs as there are always errors in the process, even timing errors in the dual A/D's of the soundcard.


I just wish the FCC-2 went to 30 MHz so I could easily cover the 40 M band. Or so I could use it with the Tayloe to look at the 5645 KHz first IF of the R4C.  I guess I will have to come up with that tripler for the FCC-2. The other choice is undersampling. Have'nt tried that yet.

[WA1GFZ]

The FFT display is much nicer than a sweep. You can see modulation a lot easier due to faster update. I would never go back to a sweep.

[Pete, WA2CWA]

And, if you want to keep the PC out of the shack:

Design Notes on a Panoramic Adapter/Spectrum Analyzer, Feb 1983 Ham Radio

Low-Cost Spectrum Analyzer with Kilobuck Features, Sep 1986 Ham Radio

A Spectrum Analyzer for the Radio Amateur, Aug & Sept 1998 QST (also available as a PDF on the ARRL site)

Panadapter Converter, March 1967, 73 Magazine

Build A 0-60 MHz Spectrum Analyzer, Aug. 1982, 73 Magazine

It think CQ Magazine also had some construction articles and/or mods (i.e. use a scope as a panadapter with some add-ons). Or, you can just grab a HO-13 or SB-620 schematic and build one of those or something similar.

[Opcom]

I like to keep the PC off in the shack unless decoding some SSTV signal or something. It's a 500MHz unit, slow.. and runs windows 2000. It would grind to a halt with XP, and not enough memory.

The application is exactly to connect to the 1st detector of a receiver and show me what the receiver is looking at. It is interesting to me to look at the signals on the band individually rather than as a group. I have discovered alot of suspicious junk embedded discreetly in the transmissions of SW BC stations. Plus, the computer is an ugly looking thing next to the R390 or SX-28.

I am not above giving the soft rock a try. I noticed in the schematic it has a 7-12MHz filter up front, and it has a crystal to control its frequency, so it must have to be modded to snoop a 455KC spectrum unless I am missing something. I will go check the FCC-1 and 2, and aso try to find those articles. Not made up my mind, i appreciate all the comments; it's obvious I have much research to do.

[KF1Z]

I like to keep the PC off in the shack unless decoding some SSTV signal or something. It's a 500MHz unit, slow.. and runs windows 2000. It would grind to a halt with XP, and not enough memory.


I am not above giving the soft rock a try. I noticed in the schematic it has a 7-12MHz filter up front, and it has a crystal to control its frequency, so it must have to be modded to snoop a 455KC spectrum unless I am missing something.

That PC would run softrock ok... no problem there....


If you're looking at the softrock-lite v6.2 schematic (you should be), then in that respect there are indeed "mods".
Tony only drew the one schematic, and then gave values for the input BPF to use the unit on 160 through 20meters.

Sorry, I don't really consider it a "mod". Just different component values for your application.

The 455khz values are not listed there. When you order your kit, and specify what you want it for, Tony includes the correct crystal, and filter components, and they all go right on the board. There are no mods to the board itself.


Anyway, I can respect not wanting a computer in the shack.
I believe though, that even though you already have a fine reciever, you'd find some more interesting shtuff to do with the soft-rock/computer combination added into the arsenal.
For very short $$ and very little time soldering...it's quite a neat little tool.

One example, you'd be able to decode the digital broadcast embedded in the analog broadcast on those AM BC you had mentioned. (with the appropriate software, of course.)


BTW: you should be able to easily see 20kc on either side of center... maybe more depending on your soundcard, etc. \



Anyway, good luck in your search, and research!

[Ed/KB1HYS]

here's something you might like. Its called the Poor Mans spectrum analyzer.

In kit form for under 200 bucks, and supplies a waveform to a scope.

from something 2 - 2150 MHz  Looks way cool. has good reviews too.

It's on my wish list.

http://www.science-workshop.com/

 

[Rob K2CU]

Neat idea for the poor man's spectrum analyzer. I had done something similar with one of the many old cable boxes in the lab until I got the 141T. One thing to consider is the 250KHz resolution which may be due to a 250Khz bandwidth in the IF/detector. Sort of usable for VHF and UHF, but pretty useless for HF.

[Pete, WA2CWA]

here's something you might like. Its called the Poor Mans spectrum analyzer.

In kit form for under 200 bucks, and supplies a waveform to a scope.

from something 2 - 2150 MHz  Looks way cool. has good reviews too.

It's on my wish list.

http://www.science-workshop.com/

The original article appeared, I believe in the late 70's or early 80's, in Ham Radio Magazine. I bought one of these kits at Dayton back in 1989, and it worked well. In a fit of weakness, I traded it off the following year for several boatanchors. I bought another package of kits in 92 or 93 (the last year they sold them at Dayton I think), but still haven't assembled it into a finished product. Still waiting for that rainy day of desire to get this thing finished.

[Opcom]

The wide bandwidth of tv tuner and other broadband demodulator derived units has been a problem of greater magnitude than the problem of their frequency range matching the desired IF. It wouln't really cost me anything to try out the soft rock if I could order the 455KC version.

I have a decent home made spectrum monitor that covers approximately 50MHz to 900MHz. I call it a monitor because other than sweep width, center frequency, and the ability to switch the bandwidth resolution between the TV demod's video and audio outputs, that's all the spectrum stuff it does. The bandwidth resolution is way too wide even on the audio output it is 10-20KHz? whatever the TV audio FM bandwidth is. It makes a great analog cable TV tuner.
Come to think of it, that poor old thing is sitting out in the shop, has not beed turned on in years. It took me a couple months to build it back in the 1980's. It's the black faced item on the lower left.