Bob,
Continental has paralleled more than two tubes in some of their
commercial application transmitters. Of course, this is in
older technology, but the Continental 105B, a Doherty amplifier
system, uses 4 each 5682 tubes in the carrier section on one side and
four more 5682 tubes in the peak section on a side. (The complete
transmitter uses 18 each type 5682 tubes in the normal configuration).
These sets of four are hard parallel, with some minor peak current
limiting resistors in the plate circuit for each tube.
Granted, tho, this transmitter operates in the AM broadcast band,
not at higher frequencies, as HF.
Sheldon
WA4MZZ
Bob Marston wrote:
>
> Lane
>
> You can take the "Good Buddy" crack many different ways. Parrallelling
> tubes increases IMD products as well as output capability. One there is no
> rule written in stone on this matter but up until recently 2 tubes was
> considered the maximum "acceptable". Going beyond that is Dirty
Engineering
>
> 73s
>
> Bob
>
> ---
> Submissions boatanchors@qth.net
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