>
>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.
Amen
>May not be a big problem on SSB, but on CW with the vox
>it will add up to burned contacts before long.
With modern radios, there is no difference in delay between SSB VOX, SSB
PTT and CW. The net result is typically hotswitching, The fix is to use
a npn transistor switch in place of a conventional relay in the RL
Control line. See Figure 7 on my Web site.
>
>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.
>
The Heath SB-220's relay can not be protected because it is too slow.
However, the Heath relay works well in step-start service. /see Figure 1
on my Web site./
>
>73, Pete N4ZR
>Contesting is!
>
>The World Contest Station Database
>is waiting for your input at
>http://www.qsl.net/n4zr
>
>
>
>--
>FAQ on WWW: http://www.contesting.com/FAQ/amps
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>
>
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|