What is this goo? RCA CTC9 chassis

[Popester]

Normally the CTC 9 chassis is on its side when used in the tv. This is one of my projects to someday get to. Presently for about the last 10 years it’s been just sitting on its base. What is this goo coming out of the transformer? Does it mean the transformer is bad? See enclosed photos.

[Electronic M]

Tar.

The transformer is potted in tar inside that square black can. If the transformer gets hot enough the tar will melt and leak out ( it is also possible for it to chemically breakdown over the years and partially seep out).

Don't let the transformer run hot enough to melt the tar... That will kill it sooner or later. If the transformer runs hot your set is drawing excessive current. Could be from electrically leaky filter capacitors or a variety of other maladies.

If your set is recapped and working perfectly but the transformer is running hot and if that set uses 5U4 rectifiers you can remove them and replace with silicon rectifiers to remove several Watts of heater winding load.

[Popester]

Thanks Tom, tv hasn’t been in service for over 12 years. Chassis has just been sitting on my old hi fi stereo which I played today. This project is for some future time. Has silicon diodes for rectifiers. Will be recapped before it ever sees electricity again. I was mainly wondering if this goo is hazardous like pcb or something bad. Hoping this transformer is still okay. I had it on this towel for the last several years and noticed the goo today.

[Electronic M]

Originally Posted by Popester

Thanks Tom, tv hasn’t been in service for over 12 years. Chassis has just been sitting on my old hi fi stereo which I played today. This project is for some future time. Has silicon diodes for rectifiers. Will be recapped before it ever sees electricity again. I was mainly wondering if this goo is hazardous like pcb or something bad. Hoping this transformer is still okay. I had it on this towel for the last several years and noticed the goo today.

It could be hazardous... most materials used in the tube era were....lead solder, asbestos insulation, cadmium chassis platting, etc etc (hell 70% of products today are known to cause cancer only in residents of California).... don't eat the towel or dust and you should be fine.

[dieseljeep]

Originally Posted by Electronic M

Tar.

The transformer is potted in tar inside that square black can. If the transformer gets hot enough the tar will melt and leak out ( it is also possible for it to chemically breakdown over the years and partially seep out).

Don't let the transformer run hot enough to melt the tar... That will kill it sooner or later. If the transformer runs hot your set is drawing excessive current. Could be from electrically leaky filter capacitors or a variety of other maladies.

If your set is recapped and working perfectly but the transformer is running hot and if that set uses 5U4 rectifiers you can remove them and replace with silicon rectifiers to remove several Watts of heater winding load.

The CTC9 never used 5U4's, only a voltage doubler.
Also, the set was designed when the normal line voltage was between 115 to 120 volts. Now, most of the line voltages are running slightly above 120 volts so the transformer will run a little hotter.

[Electronic M]

Originally Posted by dieseljeep

The CTC9 never used 5U4's, only a voltage doubler.
Also, the set was designed when the normal line voltage was between 115 to 120 volts. Now, most of the line voltages are running slightly above 120 volts so the transformer will run a little hotter.

I'm probably confusing it with the CTC7....then again I've owned every Roundy color RCA except for CTC7-12 so not having worked on those I know less about them.