> >$140+ to Ameritron. I used some relays that I had purchased from All
> >Electronics for $1.50 each; they are "power relays" with contacts rated
> >15a at 120 VAC. After all, 1500 watts into a 50 ohm line is only about
> >280 volts and 5.3 amps.
> >
> >Hey, if it worked I'd be in the miser's hall of fame. However, what
> >happened is that the relays got quite hot after about 15 seconds at the
> >1500 watt level.
I've seen large open frame 30 amp relays overheat at 1500 watts. The low
frequency AC or DC switching rating of a relay has almost nothing to do with
how suitable it is for RF applications. I have some small fifty cent relays
that will handle the equivalent of 20kW CCS into 50 ohms at 50MHz, and some
fifty dollar two pound relays that overheat at 1kW.
The same is true for rotary switch ratings.
73 Tom
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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