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Recapped My Predicta Tandem, I don't know what to do
#63

So I'm home on quarantine and I decided to poke around in my set. I replaced all the resistors in the video amp and 3 had drifted up significantly, but it made no real difference. Then I noticed I'm not getting 400VDC on the 3CB6 video amp tube in the CRT shell. So first I checked the wire going into the .22 cap and only had 203VDC. According to the drawing I should have 400VDC going into the cap. Just to make sure I took the lead that goes from the cap to 3CB6 off and checked but the voltage going into the .22 cap didn't change. Next I noticed the blue wire that goes through the 120ohm resistor is supposed to have 250v on it. So I disconnected the 120Ohm resistor and checked it has 223v on it. Then I checked the other wire that feeds the .22 cap and it has no voltage on it. It would be the one marked at 1 on the drawing. I checked the 3300ohm, and 1500ohm resistors on the main chasis and board they test good. It looks like everything is fed by the N1 network which is brand new. How can I test it? By the way I'm using the philco drawings.


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RE: Recapped My Predicta Tandem, I don't know what to do - by apERNA1985 - 01-28-2022, 10:12 PM



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