[TowerTalk] Help with Ameritron RCS-12C

Herb Schoenbohm herbs at vitelcom.net
Sun Mar 16 17:16:46 EDT 2014

I am trying to get my RCS-12C Ameritron antenna switch interface working 
with a DX-Engineering  8-Port Antenna Switch in a 1-8 configuration. 
However the Ameritron box outputs switching voltage on more than one 
wire simultaneously even in the manual setting  via the 8 pin connection 
jack thus causing more than one relay to reference an antenna. The 
switching closures from the common main feed port to the various 
antennas are all over the place thus causing high VSWR on the selected 
antenna. One would think that Ameritron would have 12 VDC or what ever 
the switching voltage might be to only output one wire at a time but 
that is not the case.  There is however on the RCS-12C an Auxiliary 
Output DB9 connector which provides a single voltage of 5 volts DC with 
respect to ground and these are all correct and non are duplicatd on 
other ports like the Din Relay box port Unfortunately the DX-Engineering 
box type RR8B-HP Remote Antenna Switch requires a control voltage of 
10-14VDC, not 5 volts. The cable used is CAT 5 of very good quality and 
I have even made a new run with a new Din connection to the antenna 
control port on the RCS-12. All my setting inside the Ameritron are 
simple 1 through 8 switching.  I have searched for solution and maybe 
the only way the RCS-12C will control the DX=Engineering Antenna Switch 
is by building a board of 8 five volt relays which then send 10-14 volts 
out to an external supply.  Yes the Ameritron 12-RCSC has provision for 
inputing up to 30 volts and an internal jumper for a direct feed to the 
Din relay box connector.  However there is enough voltage on non 
switched wires to cause the remote antenna switch to do all sorts of 
unfortunate things.  Sometime the 20 meter antenna shows up on position 
8 even though the coax is into port 5.  Sometimes the 10 meter port and 
the 160 meter port are cross connected.  This is all very strange and I 
would like to know if any other user of this configuration has had 
similar problems and discovered solutions.  I have even purchased a new 
RCS-12C controller and this performs the same way.  Again I have a BCD 
connection to my Icom but this is not the problem  since the bad 
switching occurs in manual mode  as well as auto mode.

Please let me know if you have a solution to this.  I would like to get 
it running before the CQ WPX contest or else try to switch this box with 
some clip leads and a 12VDC supply.  This must be something simple to 


herb Schoenbohm, KV4FZ

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