[CQ-Contest] [RTTY] Mono band amps

[peter.voelpel]

I did it similar with my lowband amp, one common input,
but 3 outputs, 3x Pi-L and 3 antenna relays.
The Pi-Ls sitting on a relay rail connecting the tube output
to the band used 160/80/40.
The highband amp using the same concept is under construction.

73
Peter

-----Original Message-----
From: cq-contest-bounces at contesting.com
[mailto:cq-contest-bounces at contesting.com] On Behalf Of VSH-RW4WZ
Sent: Sonntag, 22. Januar 2006 19:44
To: cq-contest at contesting.com; RTTY List
Subject: Re: [CQ-Contest] [RTTY] Mono band amps



> Subject: [RTTY] Mono band amps
>
>
> Wondering... For those who like to change bands a lot.
>
> Rather than spend between five and ten thousand dollars for an
> auto-tune amp like the 87a or similar, why not build separate amps
> for each band and switch them? You wouldn't need auto-tune or even
> manual tune since they would already be tuned. Also, SO2R would be a
> natural since no additional amp would have to be purchased.
>
> The Russian GS-35b is so inexpensive these days it seems to make
> sense to me. One power supply could run them all (for single ops
> where only one TX is allowed at one time) and just switch to the one
> you need. Fan noise might be an issue if all five were left running,
> so a pair of 3-500s or some other instant-on tube could be used
> instead. That expensive bandswitch would be eliminated, although you
> would need to switch the input and output coax, easily done with
> inexpensive relays.

Good idea, but it seems for me it will be cheaper and easy to build  PA
using
one tube and 5 PI networks which is switch by 10 relays......
We build  30 years ago such a kind  PA at UK4WAR ;)

73!

Larry

RW4WZ


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