Hi Julio: A friend KD7OY just had exactly the same problem. We found that
the relay contacts which short the amp T/R line were welded
together.holding the amp in the xmit mode even when he switched the
transceiver to receive. It is possible that the relay in your 930 is welded
shut. Pull the cable plugged into the back of the 930 and I bet the received
signal will be normal. It is very sad that many linear internal bypass
relays use voltage and current which overload the puny relay contacts in the
transceivers, particularly when there is a capacitor across the relay line.
It is very wise to use a power transister to pull the linear relay to gnd
operated by the transceiver. Harbach Electronics sells a suitable small
board for about $20 with an optical coupler and pwr xstr to do the job. I
described a circuit to do this earlier today in an amps post and Measures
has a similar circuit on his web page. If the relay is stuck shut, you may
be able to find a +12v on xmit signal somewhere on the back of the 930 to
operated the power xstr. 73, Dan, N5AR
----- Original Message -----
From: JULIO C ROSA <kapyd@juno.com>
To: <amps@contesting.com>
Sent: Tuesday, January 21, 2003 9:56 PM
Subject: [Amps] RE: Problems with Heath SB-220
> Hello Everybody!
> I want to thank everyone who kindly replied to my question as to how to
> connect the Heath SB-220 to my TS-930 and for the additional advise.
>
> I also want to thank Pete- N4ZR for suggesting to replace the meter board
> in the SB-220, in order to solve the problem of the decreasing high
> voltage reading. After replacing the meter board, the high voltage
> reading went right back up to the specified 2,500V ( CW/TUNE ) and 3,000
> ( SSB ). Thanks Pete !
>
> I wish I could say that all is well with my SB-220, but it is not ! As
> soon as I tried to put it on the air, after carefully following the
> tune-up instructions and so for, I notice that as soon as I turned the
> SB-220 on, the signal reception went down considerably. Stations in the
> S9 signal strength, went down to about an S4, and the others, either
> disappeared or were rendered unintelligible. When the amplifier was
> turned off, the signal reception went back up to normal. I tried cleaning
> the relay contacts in the unit , but everything remained the same. Am
> also becoming a TV celebrity in my own house, when am using the
> amplifier, but my wife is not too delighted with the idea of having to
> listen to me on the set, and watching the diagonal lines on the the TV
> screen.
>
> I will very much appreciate all the advise I can get, to cure those two
> problems and and any suggestions as to where to get any parts if needed.
>
> Thank you in advance for all your help !
>
> Best regards !
>
> Julio Rosa AG4HT
> kapyd@juno.com
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