doshhan wrote:
>
> > ADDED TOPIC
> > Why not use two PI-networks? One for, let's say 6-10-15-20m and the other
> > one
> > for the 40-80-160m bands? Switched with a vaccum relay.
> > Of course more parts and more space, but alot easier to handle the few C1-C2
> > pF's
> > needed for 6 and 10m, and the many pF's needed for 80 and 160m.
> >
> > I think the really ultimate home brew amp would have different PI-tanks for
> > each
> > band arranged around the tube. (If size isn't a BIG matter)
> > One tube with 7 PI-tanks, each one tuned to your favourite QRG on the band,
> > switched
>
> I have an old QST article (maybe it was HRM) from the 70's called 'The
> Ecology Linear amplifier' where the author did just what you're thinking
> about. A single 4-1000 feeding 5 or 6 separate Pi tanks. He used some weird
> scheme with a telephone dial to switch the tanks in and out as he changed
> bands.
>
> Phil T
> VE3OZZ
------
Why not switch in fixed values of C in place of a plate tuning
cap and use a roller inductor for the "plate tune".
Come to think of it, Henry radio did that a decade or two ago.
73, Bob, W5AH
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|