Stabilizing a TS-18

[compucat]

Originally Posted by Eric H

They really shouldn't be unstable if they've been recapped.

I would suspect a drifting resistor in the Horizontal or Vertical circuit (depending on which problem you are having) They use half of a 12SN7 for Horizontal AFC so I would check closely around that tube for a problem (the tube itself could also be the problem).

Sometimes heating the resistors with a soldering iron will quickly expose the ones prone to drift, you can do that with the Mica caps too but don't get carried away and melt them.

In my case the set is completely recapped and all the resistors in the sweep circuits and high voltage were replaced. The set has been very reliable but the vertical hold has always been prone to drifting for about the first 15 to 20 minutes of use. I wonder if this is just a design characteristic that was to be expected in an economy set of this vintage.