G3CWI@aol.com wrote:
>
> What sort of full break-in circuit is the best? Has anyone tried PIN diode
> switches at the multi KW level of are vacuum relays the only ways to go?
I've had very good results with my single 3-500z using the vacuum relay circuit
described on Rich Measures' web site <http://www.vcnet.com/measures/>
I used a 150v current-limited supply and Kilovac relay. I key the amp directly
from the 12v tx output of my TS850s (Rich's circuit includes a transistor switch
to make this possible). I hooked the amp to a scope, and saw no spikes or other
evidence of hot-swiching up to 50 wpm dits. I've been using this system for
about a year now. A concern is that the relay is rated for 2 million
operations, which actually could be a relatively short time if the amp is used
full QSK for serious contesting. I'm not a 'serious' contester, and I often use
semi-QSK for casual operating, so I can't report on this.
I have no experience with PIN diodes, although I know that the areas of concern
here are damage from static electricity and voltages resulting from high SWR
(like the time I sent a whole 40-meter transmission into the 20-meter quad).
73,
Vic, K2VCO
Fresno CA
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