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PA oscillation in The Yaesu FT-747/FT-80C

AudioShockwav

Extraterrestrial
Staff member
Apr 6, 2005
10,373
11,843
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Sierra Nevada by Yosemite National Park
Many Yaesu FT-747GX/FT-80C presents this fault. But it is very easy to repair.

On the PA output transistors base to colector, there are R17 and R18.

Cut the tracks betwen the transistors base and these resistors and install a little coil wound about 5 or more turs over a 100K resistor.

It will cure the PA oscillation.

This Mod Provided by:
PY8ELO

73
Jeff
 
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Thanks Jeff, I have the same problem on the YAESU FT 80C, I have tried, and succeeded,

regards 73 de YB3FTD
 

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  • @ heartbreaker3473:
    Hello gentlemen and Ladies. I have the dreaded RCI-2990 receive issue where my radio gets distorted when people get close to my location. I found the C90 Capacitor, but I can not for the life of me find the C89 capacitor. Can or does anyone have a picture of the exact location of C89 ? Thank you in advance, Wes
  • @ AudioShockwav:
    Wes, it's better if you start a thread on the main forum, more people are going to see your question.
  • @ heartbreaker3473:
    Okay, sorry, will put in a forum
  • @ heartbreaker3473:
    I put it in the general disscution help area and started a new thread. Thank you for letting me know.