Re: [drakelist] TX4C Power Output problems

[wb4hfn]

Larry,  you may want to check the final screen grid resistors.  there is a 
separate resistor going to each tube from B+.      I had a similar problem with 
a T4XC I was repairing.    The problem was traced to one of these resistors 
which over time developed a hair line crack.     Looking at the resistor it 
looked okay but moving it around just a little it quickly broke in half.    
This was my intermittent or changing power level problem.


Ron / WB4HFN

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I just aquired a TX4C that is having some quirky problems. When I put the transmitter into

the Tune mode after it's tuned, the power will jump to 100 watts and then drop down to 60 watts

after approx. 10 seconds. If I then tweak the gain control to a higher postion (ie move CW) the power

will return to 100 watts and stay there. I've taken the rig to a friends house who's very sharp on these

tube types. After poking around he discoved that the problem may be in the sidetone generator circuit.

He was able to see that the tune signal drops off as it enters the tube (can't remember the tube number)

and I was also told the my mic. audio was getting distorted as I was using it. (I imagine if I had increased gain

in may have come back) Also, when I tried to use the rig in CW mode the rig would go into transmit mode and

then drop out quick, just a beep and back to receive, irregardless of VOX setting.

 

Has anyone had this type of problem or any ideas?

 

Larry W0FLY

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