C-QUAM exciter schematic wanted

[rpapps]

Hi all
Does anyone have the schematic for the original Alfredo Torrejon C-QUAM Exciter/Transmitter or the Chris Cuff version, The Alfredo Special "Lite" C-QUAM Exciter/Transmitter?
Thanks
Rob

[Jack Crow]

Rob,
Why would you want one of those?
Even the best ones were only fair.

Then again I have a bias on the subject. I worked for Mr. Kahn back when that was business, and got to hear some of the gastly flaws in CQUAM. The ISB AM stereo was vastly better.

I see some CQUAM type exciters from time to time on EBAY.

Most of the ones I know are cut for 10khz channel spacing.

If they are made like Mr Kahn's stuff, there are a lot of custom tuned circuits in them. (I don't want to tell you how many hours I spent in front of the Q meter making those just right)

What Im getting at is if memmory is any good at all, your home country uses a 9khz channel spacing, and the retune job on that might be a real bear w/o factory data that's not likely to be forthcoming.

Let me know what your think, or if Im wrong.

later dude
Jack Crow in Kuwait

[rpapps]

Hello Jack
I've enjoyed reading some of your stories in the Engineering Humour thread.
I'm going on a bit of a nostalgia trip and reviving some of my old projects like analog Dolby surround and high quality AM stereo receiver. I was able to help out another member from Norway recently with a working CBS SQ decoder (30 year old technology).

AM stereo never really took off in Australia as it was eclipsed by FM stereo which we got much later than the rest of the world.
I just want a small C-QUAM genegator to exercise my receivers.
I downloaded a manual for a DELTA ASE-1 exciter but it is way to complex for what I want.

I could design one from information available but prefer not to re-invent the wheel if there is a simple solution available.
Cheers
Rob

[Jack Crow]

Ok,
Now we are closing in on the issue.

For a while Boonton made an AM stereo signal generator, and so did Panasonic. Check with Kenwood as well.

A broadcast exciter (like what Mr Kahn made) needs an external modulator to make the L+R on the transmitter. The L and R were in the ISB.

If you had a CQUAM signal generator, then you might be well ahead of the curve since that will be doing all the AM functions.

Kahn's exciter made no more than five watts. That's way too much to try and shield to tune up recivers.

Another thing that was a problem was pilot tone. I forget the particulars but CQUAM was at 25 hz and Mr Kahn's was at 15 hz.

Those are the two that I know about. People are still making AM stereo car radios, so someplace there is a surplus signal generator to be had.

Much luck
Jack Crow in Kuwait

[rpapps]

Thanks Jack.
All good suggestions but I'm really looking for a DIY solution as I'm on a limited budget. Somebody must surely have these schematics.
Cheers
Rob