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Phil, there's something I was gonna suggest earlier to see if the osc can be coaxed to run, but thought the better of it until seeing the CTC-2 schematic. The CTC-2 has the osc plate clamped hard with a .01 cap.
Try disconnecting the CW xfmr's primary completely, and shunt directly across where the primary was. Bypass cap C211 is now clamped directly to the plate. This duplicates how the CTC-2 osc plate is wired.
Bring the scope probe next to L42 to see if the osc is running.
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If not, maybe try a few higher values for R250 up to 39K to see if it makes any difference.
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If still no go, maybe there's a conductive track inside the tube socket itself. Most likely lugs 3 and 6 (cathode and G1). If you disconnect those two lugs (no tube in socket), they should show infinite resistance to ground, verifying no conductive path.
Then (with lugs 3 and 6 still floating) power up and see that there's no positive voltage on them, verifying no leakage path from G2 or plate lugs.
If the socket shows good, I dunno what else would be revealed by breadboarding. But what the heck...
Last edited by old_coot88; 04-28-2015 at 10:07 PM.
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