RCA CPA Color Prototype
 

Pardon me for not posting to the original thread, but I can't find it.

It has been a while since I've had time to work on the CPA prototype that Nick Williams owns. When I left it in July it was producing a raster and a black and white picture.

Since then, the original CRT that came with the chassis has gone to air, so we are using a 15GP22 instead. Getting the chassis to work with the 15G was easy.

Next was to get the color demodulators working on NTSC. Today I got the set to produce a NTSC color bar pattern for the first time since probably 1953.

You can see the restoration of this chassis here:

http://www.earlytelevision.org/rca_cpa_restoration.html

Awesome !

Just had a look, totally awesome to see the CPA prototype chassis operational!!!:D Great to see it is adaptable to the 15GP22 as well. Not forgetting about the original tube that sadly went to air, I do still hope there's a feasible chance RACS can rebuild it like they can with a 15GP22. Anyhow awesome job, (via the web) we got to witness the prototype tube operating now we're witnessing the CPA chassis in operating condition! :D

Next step is to make it work with CPA. That should be relatively easy since all the circuits are now working. All we need is a CPA signal source and a multivibrator circuit.

Wow. It's fascinating to follow the detective story and watch this unique set come to life.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Are you going with a dual format NTSC-CPA set or just going to wire it for CPA?

I think it will be a CPA set. It would be very difficult to make it dual format - crystal frequency is different, too many modifications would have to be done to allow switching between formats.

There are plenty of NTSC prototypes out there, but this is the only CPA one.

I've very much enjoyed your description of your trials and tribulations on the CPA prototype. Your troubleshooting skills are first rate. Thanks for taking the extra time it takes to document this saga for the rest of us.

That is great news Steve! Great to see an NTSC picture on that and soon a CPA picture.