[TowerTalk] Fwd: Fwd: Problems with Ameritron RCS12 solved

[Herbert Schoenbohm]

Some time ago I posted a problem I had with the RSC12 8 position Antenna 
switch controller sending out phantom voltages to the switch causing the 
extra relays to close by accident.  Measuring voltages at none switched 
ports using the 8X1 configuration demonstrated that their existed enough 
voltage on unused ports to close extra relays inside the switch box at 
the tower accidentally.  Of course this cause all sorts of problems with 
the amp protection circuit shuting down my Alpha 87A due to high VSWR.  
This problem was consistent with three Ameritron switch boxes I 
purchase.  With the help of Joe, W4TV the problem seems to stem from 
insufficient pass transistors cut off in the RSC12 controller.  I sent 
one of the units back to Starkville for evaluation and repair about four 
months ago but so far no reply on how they intend to fix the problem 
which Joe feels might be repaired by simply changing the values of the 
voltage divider on the input of each pass transistor for a more dynamic 
cut off.

Out of frustration I purchased a DX-Engineering 5KW remote antenna 
switch model DXE-RR8B-HP which considerably was more rugged than the 
Ameritron 2KW unit.  Unfortunately the problem with the phantom voltages 
was still taking place using the Ameritron RCS12C controller.  Then I 
though about using the RS-232 on this controller output to key some 5VDC 
relays that in turn would sent out 13VDC to the correct ports on the 
DX-Eng box.  Unfortunately the RS-232 output is just a voltage high and 
not enough current to close any miniature relay.  Then it dawned on me 
that what I needed was  a simple "electronic relay brick" that is a 
common item for  remote control for many Arduino applications allowing 
the control of high power devices with total isolation from the 
switching sours.  I went to eBay and quickly bought an 8X1 "brick" for 
under $20.  Installation is simple and the unit even has status lights 
showing which relay is sending out the antenna switching voltage.  In 
fact such a device may be perfect for direct interface on contest 
programs like N1MM.  My antennas are automatically tied to my Icom which 
drives the Ameritron RSC-12C controller.  This allows me the flexibility 
of an override to any band like 40 and 80 where I have both vertical and 
horizontal antennas.  This system also allows for far away remote 
operation for NP2P by simply bringing up my Icom RS-BA1 on any computer 
screen via Ultra-VNC and Yuri just points and click at the needed band 
while operating the station via Remote Rig and a TS-2000 from an 
apartment in Brooklyn.

I highly recomend the Arduino electronic relay brick interface which 
lends itself perfectly to the 8X1 outputs available with the RCS-12 
contoller along with the DX-Engineering 5KW antenna box at the tower. 
Maybe DX-Eng will someday offer the Arduino power switching 8X1 unit in 
their catalog as a perfect add on to their remote antenna switches so 
they can bbe controlled by almost any radio without serious modifications.


Herb Schoenbohm, KV4FZ