[Amps] Questions about Amp Supply LK-450

[Will Matney]

Keith,
It kind of sounds like the bandswitch on the input tank has some bad or 
dirty contacts maybe, or the capacitance of the tuned circuits has 
changed or bad. Input power is being let on through some but something 
is holding it back. About all it could be, I would think, is maybe the 
capacitance on the input network(s) or a bandswitch contact corroded, 
etc. You might ought to check the output bandswitch too, as if the 
output is off, it will directly effect the input by changing the 
impedances. Bandswitch arcing can cause problems similar in nature.

Will Matney



Hello,
I recently purchased a Amp Supply LK-450. It seems to be a good amp, with
the exceptions of a few problems. Any help would be greatly appreciated.

160m seems to have a low output, around 550 watts. The tuned input seems to
have little effect on input SWR. although the input SWR is around 1.2 to
1.5. according to my MFJ analyzer.

20m seems to have a high input swr, with low output, around 500w, and the
tuned input has little to no effect  on SWR.

10m has not been installed. The schematic gives no values for C/L/C for the
tuned input pi network. The relay is not a problem, so it would seem to be
an easy task. Just add the components for the pi network, and add the tap to
the output pi network. Although the output tap may take a little trial and
error.

All of the other bands seem to work fine with little or no touching up of
the tuned input.


Thank you,
Keith Spainhour, KT4XW