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Old March 17th 05, 03:29 PM
wb0gaz
 
Posts: n/a
Default Reducing transmit power on Yaesu FTdx560

I'm looking at the schematic for the Yaesu FTdx560 and see that the HV
winding is tapped in several places (0/340/460/600) --- I have in mind
to pick a different tap for transmit HV to reduce max power output. The
rig puts out 300W on lower bands - this is far too much for my QTH
considering proximity of neighbors - I'd actually like to have it run
at something in the 25-50 watt range (I like the rig otherwise, just
don't want to run that power output level here.) Any thoughts on
consequences of selecting a different tap for the plate voltage? Other
changes should I consider (screen voltage and/or grid bias to restore
the tube's operating point, drive level, etc.?) It seems given this
choice of taps I could even connect between the 600 and 340 point for
260VAC, or 600 and 460 for 140VAC if 340VAC proves excessive.

73 Dave WB0GAZ