AM Stereo (C-QUAM) Conversion
 

I'm ordering a Meduci AM STEREO C-QUAM DECODER CONVERTER ADD-ON BOARD for a tube-type table model radio. This would involve taking the IF signal before the detector. Is this feasible or should I purchase a transistorized table radio? This is to complement a Radio Shack AM-STEREO tuner.

Rick, this looks like a board to create an AM Stereo receiver on various modern/xstr stereo sets. The tube version is a non-starter. Tube radios of the day are not capable of AM Stereo as they have one discrete channel unless you want stereo mixed to mono on one AM frequency. A few Japanese plastic sets from the 70's did FM Stereo but not C-QUAM.

The Meduci site shows various receiver/boom box conversions that look awkward. You already have the RS receiver as do I. That is all you need for a receiver...just send it to an amp and the speakers. You need a xmtr.

And here are a few OTA stations still doing AM Stereo if you live in the area;

http://meduci.com/st_stations.html

What are you using for an AM Stereo C-QUAM xmtr? I have a kit I bought years ago at Kutztown. Here it is at the bottom of the page but I am not sure if he is still selling it;

http://www.amstereo.org/ccuff.htm

And I just bought a 1995 Cadillac with an AM Stereo radio installed. I may have to try mine to listen in the driveway. Good luck.

I copy you. I'll pursue a different tack by purchasing a recommended tuner from the list. I appreciate your reply.

Even if you don't have too many AM Stereo stations nearby, many of the C-QUAM compatible tuners have excellent FM Stereo sections in them as well. The Sansui TU-D99AMX is one of the best FM sections I've heard, while the "unobtainium" Denon TU-680NAB is a close second. I really can't judge the Marantz SR-940 at the moment as its FM tuner needs to be realigned (you have to tune 50khz above a station's broadcast frequency to get stereo), but it is a nice amplifier.

Irrespective of whether there are any stations still encoding C-QUAM (and if so, how many of 'em are not pure talkers), the synchronous AM detection, plus the proper AMAX/NAB spec for the tuner justifies their existence.

I've modified a Sony SRF42 AM stereo portable set to have its synchronous AM detector operate on receiving the main channel, good for mono station reception
http://pw2.netcom.com/~wa2ise/radios...d.html#syncdet

I purchased the decoder/converter. Let's see what's next...

BTW One of Chicago's flamethrowers is still broadcasting C-QUAM.

Really - which one?

Wls 890.

Thanks - too bad it's a talk station.

Hit the brakes! SCREEEEEEEECHHHHHHHH .......

Do all AM Stereo receivers have synchronous detection? Does my MCS 3050? The only local AM stereo is ESPN :thumbsdn: but I'd still like the Sych Detect if it has it. It would I assume reduce selective fading with CHZM AM-740 Toronto. Might even clean up normal daytime groundwave DX. Dunno. Asking.

At least in one case the inverse is true... The Sony ICF-2010 portable Shortwave receiver, which is noted for its high quality sync detection, uses nothing more sophisticated than a Motorola C-QUAM chip for sync detection. For several years my 2010 had a couple of shielded cables sticking out through the side of the battery cover for AM stereo reception (I did *not* drill holes in the fairly collectable piece ! )... Worked great!

http://users.hfx.eastlink.ca/~amstereo/sony2010.htm

jr

I was actually at a "crossroads" in the mid-80's and was deciding between the Sony 2010 and the Sangean ATS-803A. I decided against the Sony because it looked too small to be a good DX machine. :twak:

I remember cleaning out an apartment after I moved all the furniture out and the only "furniture" I had was the Sangean. Then breaking news on SW: Chernobyl. Reports from around the world on where the cloud was heading. That was a weird time in Russia anyway because Glasnost was happening and you heard some wild stuff on Radio Moscow that you'd never hear in the days of Vladimir Posner. I digress.

Here's the Motorola chip in the MCS:

http://www.videokarma.org/attachment...4&d=1433038957

http://www.videokarma.org/attachment...5&d=1433038989

edit: Here's what an AK'er who used to work at Harris IIRC thinks about it:

KAHN AM Stereo/FM Stereo "Stereo, Stereo" tuner – Post 12 - W9TR

________________

Just for yuks, thought I'd post my 1983 Sony SRF-A100 AM stereo radio. Not sure any L.A. stations are broadcasting in AM stereo anymore.

-Steve D.

Nice, I wonder if that one has synchronous detection?