Philco Prototype Color Set - Videokarma.org TV - Video

ChuckA · #1 03-14-2003, 06:05 PM

Well I decided to see if the Philco will come to life tonight. I spent the day checking the power supply and replacing the electrolytics. Right now I'm sitting here bringing the CRT filaments up. Here's a picture that warmed my heart (so far).

This is an engineering sample of the 15GP22 from Sylvania.

The filaments are running at about 4 volts in this picture

Chuck

ChuckA · #2 03-14-2003, 07:26 PM

Update for the night,

Brought the set up to full voltage, got audio, and what sounds like HV crackling but no light on the screen. The filaments didn't vaporize with full voltage, so it looks like the tube is still under vacuum.

Next - start recapping.

Chuck

ChuckA · #3 03-14-2003, 08:38 PM

Another update, for those interested.

A little troubleshooting located all 3 HV rectifiers bad. Replaced and got a raster, it ain't pretty but a working 15" color CRT made my day.

Chuck

Charlie · #4 03-14-2003, 09:48 PM

That truly unique piece of TV history is starting to open it's eyes... uh... I meant eye!

***Eric H*** · #5 03-14-2003, 10:24 PM

Chuck ,this promises to be an exciting thread!

It almost looks like you might have some video on the screen, out of sync and drifting, or am I seeing a camera effect?

Grey scale looks pretty good too!

Eric

ChuckA · #6 03-14-2003, 11:09 PM

It is some faint horizontal sync bars rolling through. The hold control was all the way to the stop.

This set is full of "black beauties" which we all know only work in guitar amps.

Chuck

ChuckA · #7 03-16-2003, 10:25 AM

Another update for the interested.

Started re-capping the two chassis' yesterday, had to stop this morning - depleted my stock.

The score so far, replaced:

66 caps - 14 more to go
8 tubes

So far all the resistors have been within tolerance

Chuck

Steve D. · #8 03-16-2003, 02:44 PM

Chuck,
I can't wait for the next installment. When do you sleep?

ChuckA · #9 03-16-2003, 03:19 PM

Quote:

Originally posted by Steve D.
Chuck,
When do you sleep?

Between 1am and 5am, isn't that normal?

And the catnaps during the day don't hurt either

Chuck

ChuckA · #10 03-19-2003, 04:15 PM

Todays update:

Finished recapping the two chassis today. Plugged everything together, and of course a new problem. Fuse blew and one 5U4 was doing a light show. Tried new 5U4 no difference, isolated it down to the deflection chassis. Pulled the chassis and power supply down to the bench looking for a solder bridge or something I did wrong - Nothing.

Troubleshooting 101 - disconnected all the connections to the B+, no problems B+ stayed where it belonged, no sparks. Reconnected a electrolytic, still good. Reconnected the line feeding the screen neutralizing coil control, B+ gone. Got close to the control and the unmistakable stench of burned control waifed up. This is a 60 ohm 4 watt center tapped wire wound control that adjusts the voltage to the neutralizing coil around the crt bulb. I guess it had burned up a while ago and when I cleaned it and moved the wiper it shorted. Of course no such animal in the parts bin, so for now I disconnected it from the circuit.

Fired it back up and this is what I have:

Charlie · #11 03-19-2003, 04:56 PM

Chuck,

Man! You got it goin' on now! That's lookin great! The excitement is building!

It kinda makes ya wonder how long it's been since the last time that set was operational? This could be this first time in decades!

ChuckA · #12 03-19-2003, 04:57 PM

Here's another picture of the screen after making some seat of the pants adjustments. Convergence is still out, especially the blue gun. Won't really be able to do much until I get the neutralizing coil connected.

Joel Cairo · #13 03-19-2003, 05:00 PM

WOW!!-- you're getting close, Chuck-- really, really, close...!!

Excellent work!!

-Kevin

Steve D. · #14 03-19-2003, 05:33 PM

Chuck,
It looks like Philco could build a color tv. And you can certainly rebuild one. Great job. What a thrill when that picture came up.

Charlie · #15 03-19-2003, 08:01 PM

This color prototype set brought a question to mind... what was the first Philco color set mass produced and put in stores? Chuck's set shows they were workin on it, but how long was it before they finally did mass produce one?

I skimmed the Sams index trying to find the earliest color schematic for a Philco. Found a chassis model TV123 in Sams 349-9 from '57... a good few years later after Chuck's set was made. Anyone familiar if there was an earlier Philco in stores? The picture on the front of 349-9 was pretty neat looking.