[amsat-bb] Completion: Re: SatPC32 Antenna Swapping with SDR

Scott scott23192 at gmail.com
Sat Jun 1 17:22:53 UTC 2019

I've had good luck with these on various projects involving 9-pin serial 


-Scott,  K4KDR


-----Original Message----- 
From: Erich Eichmann via AMSAT-BB
Sent: Saturday, June 01, 2019 12:53 PM
To: Lists_01 at kk9t.net ; AMSAT-BB at amsat.org
Subject: [amsat-bb] Completion: Re: SatPC32 Antenna Swapping with SDR

Hi Tim, a problem with that configuration:  you need access to the pins
Ground and DTR (pins 5 and 4) of the serial port to steer the buffer
interface.  To steer your Yaesu radio via the Radio 2 COM port you will
use  a USB-to-Serial converter + a Yaesu CAT cable, e.g. the CT-62. This
cable comes with a DB-9 connector on one side  that connects to the
converter and a mini DIN plug on the other side, that connects to the
radio.  So, you don't have direct access to the lines Ground and DTR.
What you could do: Solder a short cable with a female DB-9 connector on
one side and a male one on the other side. Connect the female side to
the USB-to-Serial converter and the male side to the DB-9 connetotr of
the CT-62. With that cable you  can then easily lead out 2 extra wires
to the Ground and DTR pins to control the interface.

73s, Erich, DK1TB

Am 01.06.2019 um 14:48 schrieb Tim Rife via AMSAT-BB:
> Thanks for the reply Erich.  I will give that configuration a try.
>   73,
> Tim
> KK9T
> Hi Tim,
> I have described the feature on my websitewww.dk1tb.de 
> <http://www.dk1tb.de>  , Engl. page 'Downloads', sect. 5g  (Buffer 
> Interfaces).
> You don't need a PC with a phyical COM port. The voltage at the DTR pin of 
> my USB-to-Serial converter (which generates the Radio 2 COM port) changes 
> between +6 (high) and -6 V (low), when the user switches between  v/u and 
> u/v satellites. The corresponding option in menu 'Options' must be 
> checked, of course.
> If the DTR pin is low, the buffer interface locks and the relay remains 
> open. If the pin is 'high', the interface is routed and the relay closes. 
> I do not have a transfer relay, but have successfully tested the function 
> with a 12 volt coax relay.
> 73s, Erich, DK1TB 

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