Omni VI and Computer Control

Rod Greene
Tue, 25 Jun 96 07:09 MDT

Dale, I don't think we had the exact same problem as you describe, but
here's what happened to Lee, K7QD and I on FD with Lee's OMNI VI:  We didn't
use computer control, but we had a laptop running TR for logging, and
sending CQs and the exchange, etc.  All day Saturday and Sat nite everything
worked well.  On Sunday morning, I changed the battery that was powering the
OMNI and things began acting up.  Sometimes when we tried to send a CQ, or
even use the paddle that runs through the computer, the OMNI would send a
solid carrier instead of the characters.  In checking many things over, we
finally found that the power leads from the battery (I changed their
location slightly when I changed the battery) were providing some sort of RF
feedback path that would actually key the rig solidly once the computer
started sending.  It was evidently just enough RF to only hold the keying
transistor in the "on" state once the computer started it.  Anyway, we moved
things around and eliminated the problem.  This is what FD is all about.
Next year we'll have bypass caps on the keying line!

73, Rod

At 10:14 PM 6/24/96 -0500, Dale Martin wrote:
>Field Day was interesting.  My remote antenna switch, controlled from the
DB-25 connector on the Omni worked like a charm.  The Computer Control,
however, did not.  
>We experienced many lockups with the units.  I identified the problem as
being with the Omni and not the laptop because even the keying from an
external keyer, connected in parallel with the laptop keying line, would not
key the radio.  One way to resolve the problem was to push the USB button,
then the CW button and all would be hunky-dory for a while.  Frequently,
while calling CQ or a sending a report, the laptop display would show the
out of band message. Also, and I have not had a chance to correlate it to
any particular activity, the tuning rate would drop to its lowest speed.
>Fortunately, we had a good signal and could hold our own on the frequencies
where we found productive spots, otherwise, tuning around would have been a
real problem or having to do a reset would have been worse.  We were just
about at the point where we were going to pull the plug on the
computer....the computer control interface plug, that is.  
>Anyone have any ideas?  We were running at 4800 baud.  Should we have tried
a higher or lower baud rate?  Anyone else experience and solve a similar
>When the computer control interface worked, it worked well.  Nothing like
being able to change bands with the press of two keys (alt-f1/alt-f2) or one
button (keypad bandswitch) and everything (computer, radio, antenna)
changes.  Neat!!
>Next year, two tribanders, a 40m beam, maybe, an 80m inv vee.  With a
switch to select either (NW or NE) or both tribanders.  
>Also, this was apparently the first time some of the Texas DX Society
members had an opportunity to operate an Omni VI.  The comments that I
received about its performance (outside the lockup problem--everyone else
blamed the computer) were very positive.  That was very reassuring. 
>Dale, KG5U
----- Rod Greene,, <>< -----