12-16-2021, 06:40 PM
I think you mean '47 output, not 17. Type 17 is a triode similar to the 27 except it has a 14V filament. It was designed for use in Philco model 46 and some other 115 volt DC-only radios.
True, some service info called for a 260 kc IF in the model 90 with single 47 output, but that is in error - both the first (2-45) and second (1-47) versions of the 90 have a 175 kc IF.
Now, if an IF transformer in a 70 won't properly adjust at 260 kc, I would suspect the IF transformer itself - did someone pop in an IF from an early or mid 90, or from a 112 (all 175 kc IFs)? I think it would have to be either the IF transformer, or something wrong with the trimmer condensers.
All model 70 sets were designed with an IF of 260 kc. I've serviced dozens of Model 70 sets and never had that issue.
True, some service info called for a 260 kc IF in the model 90 with single 47 output, but that is in error - both the first (2-45) and second (1-47) versions of the 90 have a 175 kc IF.
Now, if an IF transformer in a 70 won't properly adjust at 260 kc, I would suspect the IF transformer itself - did someone pop in an IF from an early or mid 90, or from a 112 (all 175 kc IFs)? I think it would have to be either the IF transformer, or something wrong with the trimmer condensers.
All model 70 sets were designed with an IF of 260 kc. I've serviced dozens of Model 70 sets and never had that issue.
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Ron Ramirez
Ferdinand IN
