At 02:07 PM 2/1/01 -0800, Bill Putney wrote:
>
>Eric,
>
>My Henry 2KD-2 doesn't have a standby switch either. Also the relay driver in
>my exciter is a transistor which would marginally drive the keying relay
in the
>PA.
>
>I solved the problem by getting a little box that sits on the desk next to
the
>exciter. A small relay in the box takes the keying line from the exciter
>through a miniture toggle switch that acts as a operate/standby switch for
the
>PA. The contacts then drive the keying line to the PA. I don't have to worry
>that the exciter driver transistor will be damaged and the box has become a
>place to put all the little things that I needed in the station (a matching
>transformer for a desk mike and a jack for a key that remotes the jack
from the
>back of the exciter that's hard to get to).
Ah, so the idea is to leave the filaments on while transmitting through but
not using the amp. Got it. In that case, I'd suggest that instead of
using a relay to switch the keying line (if I understand Bill's set-up
correctly), that you just use the toggle switch itself to open that line in
"standby" and close it in "operate". Cascading two relays will only
exacerbate the problem the SB-220 has with hot switching by delaying its
T/R relay closure. May not be a big problem on SSB, but on CW with the vox
it will add up to burned contacts before long.
Many modern transceivers have a +12v output that comes on a couple of
milliseconds before RF appears. You can use this to key a transistor
which, in turn, keys the original TR relay. At least that way there will
not be measurable additional delay, and you may actually gain a little
protection for the SB-220's relay.
73, Pete N4ZR
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