[Elecraft] KPA500 switching ideas with a Flex-5000A?

[Dick Dievendorff]

This seems awfully expensive.

Array Solutions doesn't spend that much for the relays inside their Six Pak.

Top Ten devices doesn't spend that much for the SPDT relay inside their A/B
station selector.  That unit goes for $77, and that includes a nice box and
the connectors.

The T/R switch within my Ameritron AL-1200 doesn't cost that much.

Wouldn't a sealed or frame relay do the job?  600 watts into a 50 ohm
resistive load is 12 Amps.  20A DPDT frame relays can be acquired for a lot
less than a coaxial relay.

SPST relays cost even less.  KK1L uses relays that are advertised at about
$3.16 each in his 2 x 6 antenna switch. 

Is it necessary to operate concurrently on HF and 6 meters?  Wouldn't a
couple of SPST relays suffice for this application?

100 watts into 50 ohms is 2A. You can use a much smaller relay on the 100
watt exciter to amplifier side. I'd use 5A relay. 

73 de Dick, K6KR


> That can be accomplished with three DPDT coaxial relays such as the CX800M
($159/ea from http://www.rfparts.com/coaxial.html ) $477 total

> It can be done with two coaxial transfer switches but probably cost more
(KC 1420-820 from
http://www.surplussales.com/Relays/rfcoaxialrelays/rfcoax_n.html

are $275/ea. ($550 total)