[TenTec] About the ACOM/Orion

[NJ0IP]

The ACOMs were tested by Peter Hart of RSGB and his comment was that they
are one of best amps he's ever seen.

In my opinion, there is almost no difference between the quality of an Alpha
and the quality of an ACOM.  My contesting club (BCC) probably has about 25
of each type and they are all good amps, but we have experienced problems
with both (as with any and every vendor's products).

If you compare Alpha's top automatic (legal limit) amp with ACOM's top
automatic (legal limit) amp, the difference (to the best of my knowledge) is
found in two areas:
1. The Alpha uses PIN diodes for T/R switching and the ACOM uses vacuum
relays
2. The ACOM uses more sophisticated fault monitoring, especially with this
ACR FAULT that is currently pestering many OM.  The ARC FAULT on the ACOM
has nothing to do with tube flashovers, but rather flags a condition where
RF is seen at its input when the relay is not settled in the TX position.

Duane, sorry but your patriotism is blurring your vision.  Other mothers
also have pretty daughters!  I won't go into the details of the differences
in the monitoring circuits on this open forum but can forward stuff offline.

GUYS, BELIEVE ME, the "right people" in the "right places" are working very
hard on this issue.  It's "front burner" and I believe we are very close to
confirming the actual cause of the ARC FAULT problem.  We already have a few
work-arounds, but they aren't fixing the problem, they're just enabling the
two radios to work together.

We currently have a very strong indication of what is actually causing the
problem and are having a couple of other hams try it to confirm.  If this
turns out to be the case, then you will understand why some people are
having problems with this and others are not.  

I am not (yet) going to discuss what we have found (sorry, not even
offline).  It should be confirmed in a day or two and perhaps one or both of
the companies involved will want to make a statement.  I don't want to take
the wind out of their sails.

In answer to the speculation about whether the problem occurs when keying
with the loop or the single cable, the answer is "both and neither".  We
found that we could key the ACOM permanently (externally) without any T/R
keying cable between the two boxes and then just apply RF from the Orion and
the problem still occurs.  It hasn't anything to do with the keying circuit.

Please stay tuned.

73
Rick