Re: FT-101 EE PB1547 Voltages
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Vince
The pin 5 voltage spec is around -150v.? A source of Tx problems is often Q3 (2sc784R) at PB 1181B RF unit.
The attached manual can help you,? Good luck
Emerson PP6EW
Em qua., 6 de mar. de 2024 às 19:54, Vincent Fischer < vf6fhellcat@...> escreveu:
Hello,?
I am new to the FT-101 world and new to the group and new to radio repair in general (and to be clear, I’m NOT an 11meter operator). I recently got my hands on a beautiful old FT-101 EE. It receives perfectly but no TX (3 watts). I have pulled all the boards and carefully cleaned all the contacts. I see no sign of damage or excessive heat in any of the components, with exception of the NEC tubes which both have some pretty dark oval staining inside. No signs of modification in this rig. I have checked the voltages on PB1547, and have found pin #2 at -72v (-60v spec), pin #4 at -21v (-20v spec) and pin #5 at -192v (-100v spec). I’m wondering if that high voltage on pin #5 is an indicator of a specific issue, or with the bias and driver voltages being within reason, could those old tubes have died from “natural causes”. Any feedback is greatly appreciated!
Vince Fischer, KN6KKZ
Ione, Ca.
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