[Icom] remote control

Tue, 19 Nov 2002 00:27:58 -0500

Using the interface referenced below, where do you apply the 12vdc?  I
have built this exact interface and it works great on my desktop, but I
use a laptop for all the logging and digital ops and can't get it to
work.

Thanks,
Brad	
AE4VJ  

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Dave, AA6YQ
Sent: Monday, November 18, 2002 11:56 PM
To: [email protected]
Subject: RE: [Icom] remote control

Icom's CI-V bus is indeed a two-conductor affair: data and ground. The
data
conductor is therefore bidirectional, implemented as an open-collector
TTL
bus. You'll need a bidirectional RS232-to-TTL level converter to allow
your
PC to interact with your 775. You can buy such units from Icom
(expensive)
or from one of several independent manufacturers, or you can build one
inexpensively yourself. I'm particularly fond of
http://www.qsl.net/civ_commander/interface.jpg , having built 3 or 4 of
these over the years for use with a 706, 735, 756, 775, and 781; if the
parts don't reside in your junkbox, you'll find them all at Radio Shack
totaling under $10. A Google search for "CI-V interface" yields a
multitude
of off-the-shelf and home-brew options. E-Bay may also be a source.

Connector-wise, you'll need an 1/8 inch male mono phono plug for the
775's
CI-V socket and a female DB9 or DB25 connector for the serial port.

Some homebrew schematics power the level converter from the serial
port's
modem control signals. While this works, be sure that the software you
choose can assert these signals, and don't omit the polarity protection
diodes; those modem control signals could be a source of negative
voltage
after starting your PC. Since you're unlikely to be operating portable
with
your 775, I'd suggest bypassing these concerns by powering the level
converter from a local 12vdc supply.

   73,

        Dave, AA6YQ

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Bill Conkling
Sent: Monday, November 18, 2002 23:12 PM
To: [email protected]
Subject: [Icom] remote control

I just bought a used but clean 735 transceiver.  I am looking to
interface it with my PC.  Where can I find information on how to do
this?  It appears to need only a two conductor cable.  But I suspect
it also requires some sort of electronic interface to accomplish this.

Thanks

Bill  (KG4TFF)
Wmsbg, VA

----
Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/

----
Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/