12-28-2015, 10:01 PM
After some new caps, a new tube and an alignment my 38-12 seemed to be working fine so I put it in the living room to see if it would run all day without a problem.
Well, it didn't. After 2-3 hours the local oscillator changed frequency. It didn't "drift", it was an abrupt shift down in frequency by about 35 Kc. I repeated the test a few times and it repeated the shift consistently.
I assume this is a heat problem and know how to test the various components to track it down, but I thought I'd ask if this is a known problem with a known solution to save a bunch of tedious testing.
Any suggestions will be appreciated.
Well, it didn't. After 2-3 hours the local oscillator changed frequency. It didn't "drift", it was an abrupt shift down in frequency by about 35 Kc. I repeated the test a few times and it repeated the shift consistently.
I assume this is a heat problem and know how to test the various components to track it down, but I thought I'd ask if this is a known problem with a known solution to save a bunch of tedious testing.
Any suggestions will be appreciated.
Charlie
