I pulled the Sender out of the Carriers No. 4 this afternoon and got it on the bench. 20 minutes later, after a careful visual examination, I could see, or smell, no trace anywhere of recent overheating.
Next step will be removal of all the valves and a complete redo of the three resistance tests for the Sender using the same VTVM I did the original tests with earlier this year. This was something I had planned to do anyway after carefully cycling the 300 and 1200 Volt power feeds from the Supply Unit though the Sender over a period of time.
There were a cluster of unusually high resistance readings in the first tests I am curious to see any possible changes in. Also, I may now find an earlier, normal resistance value that has suddenly gone south, which might point to the potential new problem. It will take a few days to complete, since access to a few of the test points required temporary unfastening and moving of some components.
David
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