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Fix for an intermittent FT-736R problem on 435 MHz



Still assembling the station here for AO-40 and developed a problem in the
Yaesu FT-736R yesterday.  Whenever the VOX relay was keyed, the power output
jumped to 42 watts on the 435 MHz band and could not be reduced with the
drive level control.  It appeared that the final was oscillating as the
output level was constant, and did not follow the CW keying.  The problem
was intermittent, but the failure occurred most of the time the rig was
keyed, either in CW or SSB mode.   144 MHz operation was normal.

The fix was to remove the final modules and heatsink from the chassis,
remove the shield, and tighten the several screws used to secure the final
circuit board and transistor module to the heatsink.  None of the screws
were as tight as they should have been.  No way to be sure whether it was
caused by the screws being loose, or a problem in one of the cables you have
to unplug to remove the module.  At any rate, the problem is now gone.  The
entire operation took only about an hour and can be accomplished without the
service manual.  If you're having similar problems with your 736 on 435,
give it a try.

K8AC
Floyd Sense - Angier, NC

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