Recapped a CTC 7AH..still have a problem

[Phil Nelson]

Originally Posted by Electronic M

If you haven't replaced the papers/or paper-milars those can some times cause troubles in early roundys.

Here is my CTC-7 after I had replaced only electrolytics. Bad horizontal, lousy vertical, colors all hosed:



Here it is after I replaced the old "maroon drop" mylar caps:



Still need to do the usual setup (convergence, etc.), but you get the basic idea.

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

[DaveWM]

Phil, can you pls confirm the resistance of the primary of the power transformer.

my 3-4 ohms is on a CTC-16

[Phil Nelson]

Sorry, mine is stuck behind a pile of stuff right now.

Phil Nelson

[DaveWM]

I discussed it with the OP, he has 0.6 ohms, which seems WAY low to me but not sure, the sams does not specify. Hope someone out there with a 7 can chime in.

[DaveWM]

hmmm well the sams says DC resistance under one ohm not shown so maybe thats right.

[47'Plymouth]

found the power tranny in the primary a dead short,probably left plugged in during a thunderstorm.."Lighting Hit!"years ago; anyone have a good replacement....tried again; unhooked the power tranny.disconnected from the set..and my Variac sparked up again with huge current drain on the Amp meter...resulting in no volts obtained when trying to turn the knob on the variac...stopped immediately to prevent damage to my variac...calling Moyers asap..any suggestions model 7 owners???

[47'Plymouth]

to answer the question Phil;
on did i replace the other caps..all are original "Sprauge"..maroon drops..the good kind..had only one "Bumble Bee"
at the plug in socket; it was a .047@600 between A/C the power pins..i replace with Orange dropall of the E-caps i had already replaced in the cans...probably a dead short in the primary it read 00.6 ohms,on my Sperry 5300 autorange DVM across the safety interlock

[stromberg6]

Originally Posted by Phil Nelson

Here is my CTC-7 after I had replaced only electrolytics. Bad horizontal, lousy vertical, colors all hosed:



Here it is after I replaced the old "maroon drop" mylar caps:



Still need to do the usual setup (convergence, etc.), but you get the basic idea.

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

Phil, Is that CRT a 21CY?

[Phil Nelson]

Originally Posted by stromberg6

Phil, Is that CRT a 21CY?

Yes, 21CYP22.

Regarding the old "maroon drop" caps, I used to assume they should be as good as new orange drops, but I guess 50+ years can take a toll on this kind, too. I didn't get a reasonable picture until I replaced them. The CTC-7 boards are easy to work on, fortunately.

Too bad about that power transformer -- ouch!

Phil Nelson