Robert Carroll wrote:
>I recently started using my old backup radio, a FT1000MP which I have owned
>for many years. The main rig was out for repair. I normally drive an Alpha
>86 or 89 with QSK pin diode switching. After scratching my head a while, I
>remembered the QSK from the MP is via a back band data jack. I hooked it up
>to the MP and it works very well.
>
>
>
>The main rig arrived back from the hospital today and the MP, for the
>moment, will be relegated to keying non-QSK rigs with conventional "keying"
>relays. While the MP has an internal relay which will handle this, enabling
>it requires getting to a small slot on the back and sliding a PCB switch-not
>nice when swapping back and forth between the Alphas and non-QSK amps-and
>that little slide switch would be very inconvenient to replace if it becomes
>flaky.
>
>Instead I would like to use the logic-level QSK signal from the MP band data
>connector to key a sold state (BJT, FET, or opto-transistor) circuit which
>would handle a conventional amplifier relay input-sort of like an external
>relay circuit you use with an old amplifier with a 110VAC relay, but solid
>state.
>
>
>
>I have seen very simple circuits for such devices on the web, and there are
>a couple of fairly inexpensive commercial ones available. I can't seem to
>locate any schematics for homebrewing one at the moment. Though I have the
>basic circuit ideas in mind, I would rather build something already known to
>work well. Can someone point me to such a unit? I don't think any of the
>relays I would need to key exceed about 24 volts dc at perhaps 100 mA.
>
http://www.ifwtech.co.uk/g3sek/in-prac/best-of.htm#speedup
Click the "April 2002" link to download the whole article.
--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek
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