[RTTY] [CQ-Contest] Mono band amps

[VSH-RW4WZ]

>
> That would be good too if you can keep the lead lengths down.

    Yes, it is very important, especially for 10 m. First we select Tube
with low output capacity. As I remember 25 pf. Then modeling the
different constructions methods to minimize the capacity value.

 Also, a
> relay to switch the plate end of the pi net would have to be pretty
> substantial ($$$).

    It depends what power You want to get ;)

 I like the idea though.
>
> Perhaps the tube could be in the center and the networks laid out
> like spokes of a wheel? That would take a lot of chassis space, but
> so would separate amps.

  We use separate PI N for each band and it stay in line. Tube was in center
of chassis. First capacitor was vacuum capacitor.


>
> Or maybe a single tapped coil and separate tune/load caps being
> switched in and out?

No, we use the separate coils for each band and tune it by special design
mechanics to move ferrite core inside the coil.


73!

Larry

RW4WZ