03-13-2026, 09:01 AM
Hello Richard,
Your suggestion was a good one to narrow down the issue, and I wish I had posted/asked much earlier, as I had suspected the output transformer, and after spending $60 found out it made no difference. Yes, a nice sine wave into the final stage became distorted at the plate at any reasonable level. I bought some 1A5G tubes, but they made no difference, i.e. low volume and the sound was clear but at any reasonable listening level distortion ("gargle"). Looking for a substitute, I noticed that a 3Q5G could be used with pins 2 and 7 jumpered and filament voltage applied between them and pin 8. I happened to have one of these, and lo and behold the radio plays nice and reasonably loud without distortion!
So again, thanks for the suggestion, (which I should have known anyway) and all is well.
Ken
Your suggestion was a good one to narrow down the issue, and I wish I had posted/asked much earlier, as I had suspected the output transformer, and after spending $60 found out it made no difference. Yes, a nice sine wave into the final stage became distorted at the plate at any reasonable level. I bought some 1A5G tubes, but they made no difference, i.e. low volume and the sound was clear but at any reasonable listening level distortion ("gargle"). Looking for a substitute, I noticed that a 3Q5G could be used with pins 2 and 7 jumpered and filament voltage applied between them and pin 8. I happened to have one of these, and lo and behold the radio plays nice and reasonably loud without distortion!
So again, thanks for the suggestion, (which I should have known anyway) and all is well.
Ken
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