[OFARC] problems with my transceiver

[Ralph]

my radio was sick and I thought I would share my experience in 
troubleshooting the problem

It turned out to be a BASIC error ......


73 - Ralph

KE5HDF


_Patient:_

I have an Icom 706Mk2G transceiver

HF/VHF/UHF all mode

radio is connected to tuner which allows me to select an antenna

nominal 100W on HF SSB


_Symptoms:_

feed back in the shack ... I hear myself talking over the radio speaker 
when I transmit

radio shuts down on AM if using over 20% power


_tests tried:_

feed back is heard on HF bands .... 20m, 40m (common antenna feed line), 
2m, 70cn

verified good ground between all equipment and shack ground bus

cut power from 100W to 20W - still present

disconnected antenna lead from tuner and checked SWR out to the antenna- 
all good

put antenna on the tuner, disconnected coax at the radio and checked SWR 
through tuner to antenna - all good

switched tuner to "dummy load" - still have feedback

took tuner out of the circuit and connected antenna coax directly to 
radio - still have feedback

checked using USB, LSB, AM on 20M and 40M

not as noticeable on VHF/UHF FM, but present

the tests run seem to rule out a coax problem........

finally noticed the power supply voltage......it was down to 12V_no load
_apparently I have bumped the knob while working near it on another 
project._

increased voltage to 13.5V no load and the radio is happy again
_

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