07-06-2022, 06:17 PM
I doubt that a 78 tube will work in this application, since the 77 is used as an autodyne converter and oscillator.
Like Terry, in my experience a 6C6 does not work for a 77, nor a 6D6 for a 78, nor vice versa.
As as Terry said, the 57 has a 2.5V heater and the heater string in model 89 is 6.3V. Not to mention the 57's heater draws more current.
Like Terry, in my experience a 6C6 does not work for a 77, nor a 6D6 for a 78, nor vice versa.
As as Terry said, the 57 has a 2.5V heater and the heater string in model 89 is 6.3V. Not to mention the 57's heater draws more current.
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Ron Ramirez
Ferdinand IN
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