[Amps] Tank tweaking - plate choke

[Guillermo]

    A question, ¿is 225 uH inductance enough for the plate choke at 160? (taking in care 3200 ohms plate load..)

Best regards
Guillermo.

Bill Coleman escribió:

> Thanks for all the ideas.  I've had a few requests for a couple bits of data...
>
> On 160 the target Q is 12, Plate load is 3200 ohms.
>
> I have tried changing the plate blocking cap from 800 pF (it was 4 200 pF HT57's) to 1000 pf and 2000 pF using some HH58's. This appears to have helped, but it's still way down on efficiency (<50%) compared to any of the other bands (even 10M - 60%).
>
> I tried changing the physical layout of the coil stock relative to the 10/15/20 meter coils. Thinking (?) there was some wierd cancelling/coupling.  No change.
>
> Next experiment will be to tune the input circuit on 160.  I didn't bother tuning either 160 or 80.
>
> Right now the only band that is troublesome is 160.
>
> Thanks all.   73, Bill  N2BC
> ~~~~~~~~~~~~~~~~