ORIGINAL MESSAGE:
On Sun, 4 Apr 2010 00:47:23 EDT, PACER99@aol.com wrote:
>
>If you agree with my thinking then can anyone suggest a simple solution to
>slow the input relay switching.
REPLY:
You need to be careful with this. It's good to slow the input relay
down on "make" but you need to speed it up on "break" or you will
still have the same arcing problem, just on the other end of the
transmit cycle. You also need to delay the transceiver's RF output.
Ideally, what should happen is:
1. Key or switch closure.
2. Amp output relay closes.
3. Amp input relay closes.
4. Transceiver TX relay closes.
And then reverse the order when un-keying. You may be able to get away
with #2 and #3 happening simultaneously *IF* #4 happens with
sufficient delay. Some transceivers have a menu item where you can set
the delay on TX start, but whether they have a similar speed-up on TX
end remains to be seen. A few minutes with a dual-trace scope will
give the answer.
All of this is easier said than done.
What you want is a relay sequencing circuit. A Google search will find
some articles, and I recall seeing circuits in the ARRL handbook years
ago. Whether they are in current handbooks, I don't know.
73, Bill W6WRT
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