Jim,
Well, at first I was indeed thinking about switching with RF, but using
e.g. a 144MHz RF signal to switch the relays in my 20/40m dipole. I had
doubts because of the possible 'RFI' that my HF signal might cause to my
UHF detection circuit. But your idea (using the HF signal itself to cause
the switching) is much better. I will be thinking some more about this. I
will keep you posted if I come up with a good solution...
Thanks,
Frank
PA4N
At 17:53 21-07-2005, Jim Lux wrote:
>At 06:32 AM 7/21/2005, Keith Dutson wrote:
> >A switch like this would typically need several ma of current to activate.
> >For this reason I would not use RF. I do not think it is practical. Use a
> >trap instead.
> >
> >73, Keith NM5G
>
>I think he was thinking about a DC control signal. However, you raise a
>fascinating idea. A small latching relay doesn't take much energy to
>actuate (a few milliseconds of 30 mA at 24V, for instance). You could have
>a tuned circuit that detects 20m and latches the relay one way. Then, you
>have another (passive) circuit that detects the 40m power and latches the
>relay the other way. Even if the relay took a whole watt to operate,
>you'd never even notice it out of the 100 or so watts you would be radiating.
>
>The overall losses of the system could be made much less than those of a
>trap, albeit there is a complexity issue.
>
>_______________________________________________
>
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