[Amps] How to connect the SB-220 to a Kenwood TS-530 and TS-930

[Pete Smith]

At 12:39 AM 12/6/02 -0500, JULIO C ROSA wrote:
>Hello!
>Can someone please describe to me how is the connection made from the
>Heath SB-220 to the Kenwood TS-530 (with TUBES finals ) and TS-930 (Solid
>State ).
>    As far as the RF cable connection I see no problem there, but am not
>really sure on how to go about making the ALC and the relay connections
>to either one of the transceivers. I rather wait until I get a sure thing
>info. I would also like to know if it will be safe to use the TS-530 with
>the SB-220. I realize that to use it with the TS-930, first I would have
>to do an upgrade on the SB-220 relay.
>  Thank you so very much for your information! Happy Holidays and best
>regards !
>

Hi, Julio.

The relay in the SB-220 is 110 VDC, a number that is too high for the 
solid-state switching in many modern transceivers.  However, I used an 
unmodified SB-220 with a TS-930 for several years.  The SB-220 relay is 
connected to pin 7 of the Remote jack.  The relay that controls that pin 
must first be enabled by moving a jumper on the relay board inside the 
radio near the power amplifier section (my memory isn't clear on this, but 
I think it is under the bottom cover.  This is explained on page 32 of the 
English-language manual, in figs 6-3 and 6-4.

At a friend's suggestion, I also used a 220 ohm, 1/2 watt resistor is 
series with the relay line, to limit the current through the relay.  All 
this worked fine.

I would not be surprised if the TS-530 had a similar connection, and could 
be used with the SB-220 in the same way.

This is not to say that the SB-220 relay isn't a weakness of the unit -- it 
switches too slowly for many modern transceivers, and that may result in 
hot switching that will eventually cause the relay to stock.  Modification 
to incorporate a vacuum relay (as described on AG6K's web page) is not a 
bad idea.

I have never used the ALC connection, and see no need to.  As long as you 
adjust the exciter so that its internal ALC indicates properly, neither of 
these radios is likely to drive the SB-220 hard enough to cause a problem.


73, Pete N4ZR
Sometimes a tower is just a tower