Hello Mike,
-
You will probably notice a lack of replies regarding
questions for your Swan 1200x amplifier. It might be
said that many folks here consider the Swan and
similar type amplifiers desktop toys or junk. They
have a place when properly operated as a cost
effective mid size (power level) amplifier in SSB
operation.
-
The common methods to key the type of amplifier
you have are to ground the negative side of the
TR relay which placed it in transmit mode. Few
amplifiers require you supply a positive keying
supply voltage to the relay.
-
A typical Amateur Radio will have a jack for
connections to external devices. A few years
back, most of the typical connections were
contacts to a relay inside the radio. Key the
radio, the "loop" or normally open contacts
from the radios internal relay contacts were
closed.
-
We now have newer generation radios with
a mixed bag of external device interface
requirements. After you locate the odd ball
plug that matches the proper radio interface
jack, you often are required to build or use
some type of small buffer (isolation) keying
circuit between the radio and the amplifier.
-
Many of the hams here "roll their own" but a
lot of the less technical folks will buy them
pre made. There are people on Ebay selling
Radio to Amplifier interface cable/circuit
interface assemblies, might be an option to
look at if you have a newer radio.
-
About your amplifier... there should be or
should have been a connection jack
(probably an RCA type jack) which has the
T/R relay negative return. When you ground
the jack center lead to ground, the amplifier
should go into transmit mode. The red
wire you describe is a wild card to me,
might be someone brought the relay
control jack connection out of the
amp.... or someone might have done a
mod for something else.
-
Carefully measure the voltage on the
wire with the amplifier on and in the ready
to transmit mode. If it turns out to be 12 to
18 volts dc, chances are it's the keying
return to the relay. If you measure no voltage
on the wire, you'll need to figure out what the
mod is.
-
Diagrams for your amplifier are probably
on the http://bama.sbc.edu web site. You
are welcome to Email me direct if you have
more questions.
-
cheers
skipp
nospam4me@juno.com
--------- Forwarded message ----------
From: Mike Bishop <ki4ame@yahoo.com>
I recently purchased a Swan1200X and I'm trying to hook it up to my Yaesu
FT-890 , the Swan 1220X has the mod. so it will work on other radio
besides the swan radios. It has a single wire coming out the back and
that goes top +1970 and I was also sent a 2 wire belden cable with red
and black wires in it. I have put a RCA jack on one end of the belden
cable and put that to TX Ground on my Yaesu FT-890 and the relay on the
radio is working, on the other end of the belden cable I put the black
wire to -12vdc but I can't figure out where to put the red wire on the
other end of the belden cable. This is the hook up I was told to do by
the person I purchased the amp from but I never could understand where to
put the red wire thats on the other end of the belden cable. I'm
attaching a drawing of the connections and maybe someone can steer me in
the right direction and tell me how to key the relay in the amp.
73's de KI4AME
http://www.carc.cc/
KI4AME
Mike Bishop
P.O. Box 922
Cleveland, TN. 37364
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