RCA CT-100 Chassis Intrigue...

[dtvmcdonald]

Originally Posted by Pete Deksnis

Two Points:


I don't have a working CTC2 chassis just now, so I can't check anything out, but on March 15, 2015, I added "Really ?" to W29 on page 3 of SAMS Set 252 Folder 11. Here's my reasoning which tentatively concluded that W29 was 'probably/certainly' not correct.

Checking the I-channel Inverter waveforms, it shows that W31 (grid), W32 (cathode), and W33 (plate) all display I-signal waveforms.

The equivalent Q-channel waveforms show that, of the three -- W29 (grid), W35 (cathode), and W34 (plate) -- only W35 and W34 display Q-signal waveforms. W29 shows a pulse. Somehow SAMS turned a pulse into a Q waveform. History: I knew the guy who set up the SAMS 'production line', as he called it, the one that produced data for the Photofact Folders. He was a publisher, not a technical guy, but I know he'd have been on top of apparent mistakes like this -- keeping such things from being repeated.

Ah, but W29 and W30 don't go with W31 through W35. W31 through W44
are color bars, in order green yellow red magenta blue. W29 and W30 don't
display those bars. They display I and Q bars, in unknown order, see Note 4.
I checked polarities with the official matrix and they look right. They look
right compared to my color +-I +-Q test slides ... (plus is first in two triples
+I-I+I Y=50% +Q-Q+Q)

Red bars are positive for both I and Q
Green bars are negative for both I and Q
Blue bars are different for I and Q

Salmon (pure I) bars are +I
Pure Q bars, +Q, are sort of violet-magenta

Pure -I and -Q are both sort of greenish, -I being a bit bluish.

Doug