[NA-User] 2 radios - 1 COM port

Carl - WC4H wc4h@itis.net
Thu, 14 Mar 2002 07:57:29 -0500

As I had said, I use CT (I'm not 100% familiar with NA nuances) so it works
for me.  I downloaded the NA demo but it's DOS and Windows XP is not great
for DOS programs.  I may have missed something in my download but I could
not find a Windows version.  I was going to say "If NA lets you put both
radios on one COM port" but decided not to.  Oooopppssss.

I agree that you turn off the transceive function unless you want both
radios to be on the same frequency.  That is what the transceive does. Let's
you turn one dial and both radios change frequencies.  It does have its

The ability to assign radio 1 and radio 2 to the same COM port is essential
to Icom users since the CT-17 is designed to use one com port for 4 radios.
It keeps the data straight based on the memory address.  I don't know that
it is intended to send data to both radios at the same time, since it only
uses one COM port.  I think the premise is that you use one radio at a time.
CT, Win-EQF, etc. also use that premise.  Hence, you toggle between radio 1
and radio 2.   There should be zero data collisions.  I find that the
interface works fine with two radios and saves COM ports.

BTW, Win-EQF lets you set up Radio 1 and Radio 2 on the same COM port but it
is not primarily a contesting program.


----- Original Message -----
From: "k8cc" <k8cc@comcast.net>
To: <wx3m@comcast.net>; <na-user@contesting.com>
Sent: Wednesday, March 13, 2002 10:56 PM
Subject: Re: [NA-User] 2 radios - 1 COM port

> If you look at the schematic for the CT-17 (at least I got one with mine)
> all four radio jacks are wired in parallel.  The CT-17 doesn't keep
> anything straight - it counts on only one device (either a radio or the
> computer) talking at a time.  This is also due to ICOM's decision to tie
> the rx data and tx data lines together.  If two devices talk at the same
> time, data collisions occur and the data gets scrambled.  This is general
> the reason why you see erroneous "RADIO OUT OF BAND" messages with ICOM
> Tip #1: Turn OFF the TRANSCEIVE function in your ICOM radio, either by a
> menu or by the DIP switch inside the radio.  This function has no benefit
> when used for HF contesting with either NA, CT or TR, but it causes the
> radio to spit out data continuously while the VFO is being turned.  This
> leads to data collisions.
> As currently designed, NA cannot do what WX3M has described.  The reason
> for this is that the serial port functions, as configured in CONFIG.EXE,
> allow only one *serial data* function per COM port.  (Note that I said
> *serial data* - you can share serial data and CW keying on a single COM
> port).)  You can't assign RADIO1 and RADIO2 both to the same serial port.
> The only guy I've ever spoken to who uses the "two radios on one COM port"
> configuration is Phil, KT3Y in VA.  He does it with CT, using (as I recall
> at the time) a IC-775 and a IC-765.  I pondered the merits of using a
> single COM port, but nobody ever asked about it.  Leave it to my friend
> (and SO2R "deep thinker" WX3M).
> Don, if you want to try it, I could kludge up a special NA version to try
> with your setup.  I'm not altogether sure how satisfactory this is going
> be, since with two radio on the CT-17 there will be more opportunities for
> data collisions.
> Dave/K8CC
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