> You'd have to see some LK-500 wiring and parts values to believe it
> Peter. Nothing would suprize me.
>
> Without seeing the wiring and the bandswitch, anything could be
> going on.
>
>
> 73, Tom W8JI
Ok Folks -
I think I have the answer on this problem. To quickly recap I'm burning a
160 meter padding capacitor on the LOAD (antenna) side in the tank circuit
on my LK-500ZA when transmitting on 10 meters. The consensus was that there
was two possibilities:
I) Bad wafer on the bandswitch and the 160 meter padding capacitor was
actually being connected to the circuit.
II) Inductive coupling ( I think this what Phil, k5pc was referring to as
"Autotransformer"). The heavy gauge leads of the of padders were parallel
and in close proximity to the turns of the 40-160 meter tank coil.
I decided to try an experiment. I went into the amplifier and disconnected
the padders from the wafer on the bandswitch. I kept the leads in the same
position, parallel to the coil and made sure that it was not making contact
with anything, just hanging in the air.
My assumption was that if the capacitor didn't burn, that it was probably
due to the bandswitch and if it did it was inductive coupling. I tuned the
amplifier on 10 meters into a dummy load and the capacitor started to fry
like an egg.
I'm assuming that it is inductive coupling. I am going to rebuild the
padder portion of the tank circuit. I am going to relocate the capacitors
such that the leads due not lend themselves to couple energy from the tank
coil (i.e., I am going to keep the wiring away from the coil).
Thanks for all your help and I'll let the group know how it turns out.
73s
Bill, w6qd
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