Questions on 1958 COLOR Raytheon C-21C1-M Television

[TQGIBTNGO]

Originally Posted by Tim

Welcome to the forum Matthew and congratulations on preserving this uncommon set. I see yours is mahogany, as is the one that I have. I understand that the other known one is blonde. It is fantastic that the CRT in yours seems to be good. I agree with the other responders that the testing issue is probably with the tester.

You mentioned 1958 but it is actually a 1956 set. There was a write up on it in the January, 1956 issue of Service Magazine beginning on page 13. The magazine is available here: https://worldradiohistory.com/Archiv...ce-1956-01.pdf

Thanks for posting your find and please keep us abreast of your progress and feel free to ask any questions. Although my set has a good CRT, it is presently unrestored.

You're right. Thanks for the correction. I misread the cabinet. That makes me even happier that it's earlier. I'm going to replace the capacitors in the tester and then go from there if it still shows a short. I have a question about the cabinet. Would having a professional wood worker fix the chunk missing out of the top reduce it's value? I'm thinking I'll just leave the missing chunk alone. Also I was thinking about using Howard's Restore a Finish on bad scratches at the very least. Any thoughts

[Tim]

You may get differing opinions but, if it was done well, I do not think it would reduce the value. It is the rarity of the set as a whole that makes it desirable, not a missing piece of original woodwork. If it was done professionally it would probably not even be noticeable. Leaving it alone for now is just fine. No rush. Howard's works well to even out the existing original finish.

[CrtsRtubular]

heres the schematic if you don't already have it:https://drive.google.com/file/d/1Y3D...ew?usp=sharing

[old_tv_nut]

Driving all three of the 21AXP22 cathodes with the same luma signal? That set must produce a very cyan picture. Even the cost-cutting RCA CTC-5 super had a resistor network to give the red gun extra oomph.

[Tom9589]

Looking at the schematic, I noticed T2, a 1:1 filament transformer which only provides filament voltage to V8, AGC Keying/Color Killer. Why a transformer for this one tube? Is it because the cathode (pin 9) is at a +200V potential?

[old_tv_nut]

That seems right. The 6AN8 spec reads:
Total DC + Peak 200v

[Tom9589]

The first model of the GE PortaColor had a similar transformer in the series filament string for the CRT to lessen the potential difference between the filament and the cathode. The one I had got a heater-to-cathode short anyway. I just removed the resistor which tied the CRT filament to one of the B+ lines and just let the filament float. Worked well until I parted with it.