Hello all !
I'm testing the homebrew W6PO amp that I just completed and I seem to be
having trouble getting more than 300 watts out of it.
Before I powered it up I tuned the input and output sections for minimum
SWR at 144.1 MHz using an MFJ-259 antenna analyzer.
I have the amp connected to an FT-847 exciter and a large Bird dummy
load. HV is between 2500 and 3000vdc on the plate. I see about 300mA
current on the plate when I'm getting 300 watts out but very little
current on the grid meter, which I find a bit odd. I 'm using a G3SEK
Triode board to provide the bias and control. I do see 12vdc bias on the
cathode during TX.
The 3CPX1500a7 tube was purchased as a medical pull. I have no way to
verify its condition so there is always a chance it's no good. This is
my first big tube amp so I'd like to make sure I'm not doing anything
wrong before I think about buying another tube.
Any guidance will be appreciated.
(Pix of the amp can be seen at http://www.va3to.com )
Thanks, Hugh VA3TO
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