AM STEREO

[ROKFRED]

Oh Boy.....that wasn't a good thing to read. And looking online I do hear clips of X-FM who uses C-Quam and the fading signal can be annoying as the pilot comes and goes. The "stereo image" was stable. I didn't detect movement. Both audio clips are below.
I think they figured out how to reduce/eliminate the moving platform effect for regular "DX" of AM broadcast stations, quite a while ago.


https://swling.com/blog/2014/02/listening-to-shortwave-radio-in-stereo/

[M R I]

Give it a try on shortwave and see how well it works for you. I have been working on a method with two independent sideband channels that would not be subject to propagation fading. The receiving method would be on SDR with standard available modes like dual receiver function.

[nitroengine]

If you have the ability to do AM-stereo, you might as well do it. Those using mono radios won't be able to tell the difference. It gives those using rigs capable of decoding C-QUAM something extra to experience. Gives you something that sets you apart from most other pirates too.

It would be interesting to see how the later advanced Motorola decoder chips handles a shortwave signal with selective fading. The later chips tackled the problem of platform motion that the early MC13020 can exhibit. Platform motion was really only a problem in the late evenings and overnight on AM, and maybe in areas where there is a strong enough co-channel carrier.

The decoder in the Kiwi is one that does exhibit platform motion.

[ROKFRED]

OK NitroEngine
At least make use of the investment of the C-QUAM generator I bought on eBay. My present 1620khz signal is using a different model Panasonic C-QUAM generator that only goes up to 2mhz RF carrier.
The latest purchase generator goes up to 280mhz.
You gave hope to continue to carry the C-QUAM torch.
Fred

[ThaDood]

When time allows, I've simulcasted my Part 15 stations' programming to the Sean Cuthbert C-QUAM AM Stereo transmitter. https://radiojayallen.com/cuthbert-am-stereo-c-quam-transmitter/   I want to change mine over to a different, metal, case. And, I've modified a Sony SRF-42 AMAX Walkman to be an AM / FM Stereo VU OTA Monitor. https://www.minds.com/group/876322093051867136/feed     (Scroll wayyyyyyyyyyyyyy down when the page finally loads-up.) I'm set-up in my audio chain for 2 Channel audio, where the only MONO sections are the AM transmitters. So someday, I hope to be AM Stereo full time.

[redhat]

Decoding C-QUAM as QAM eliminates much of the platform motion with a bump in low frequency distortion caused by intermodulation.  There were hacks to the older C-QUAM demodulator chips where you could disable cosine correction and force the chip into QAM mode.  In software this should be easy to do, and when the Kiwi folks added CQUAM demodulation, I advised them to add a QAM mode to get around the platform motion issue.  I'm not sure that this was done, however.

On HF, ISB would likely be a better choice.  You still would have phasing effects, but the complete channel reversal and wobble under fading conditions would go away.  I chose C-QUAM initially because of receiver support.  At the time, there were no software decoders available for ISB, and to date the only one I'm aware of is onboard the Kiwi.

+-RH

[Pigmeat]

Dood, our mutual friend seems to have AM stereo down pat. I listen to his station 2-3 times a week.

[M R I]

Transmitting in ISB stereo with suppressed carrier is effectively DSB mode. I mostly transmit in sideband anyway. I may get around to working on this at some point.

[nitroengine]

I'd like to hear a pirate trying Kahn ISB AM-stereo sometime.