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[TenTec] Topband: Earl's Evaluation

To: <tentec@contesting.com>
Subject: [TenTec] Topband: Earl's Evaluation
From: btippett@alum.mit.edu (Bill Tippett)
Date: Tue Jul 1 18:13:23 2003
W8JI posted this on the Topband reflector and asked that it be
forwarded to other reflectors.  If you want to reply to Tom
individually, please do so at W8JI"at"contesting.com and
replace the "at" with @.  (de Bill W4ZV)



(Maybe someone can copy this to the reflectors I am not subscribed to for
me.)

While I appreciate Earl's efforts to handle a very neglected (but valid)
consideration, I'd like to urge everyone to use caution. Don't accept one
test of one isolated factor as majority consideration when making a
selection!

This stuff has a habit of taking on a life of its own, and may influence
sales long after problems are corrected (or even if there never was a
problem).

Ten Tec seems to understand the normal AGC is not optimum, and other people
are commonly reporting they have to use programmable AGC for weak signals.

I also think the narrow filter of the TT could be a major source of
problems, but it can be switched OUT to a wider filter. It very well could
be Earl's TT just needed the AGC reprogrammed, and a different type of
filter.

The type of noise, how noise changes every hour of day, how our brains work,
and many other things can actually make results vary quite a bit.

DSP radios that do not use narrow roofing filters have the potential to be
much better on relatively empty bands, because they almost certainly have
very little group delay error in filtering compared to radios with
traditional filtering, especially sharp filtering. (I see evidence of this
in the high opinions of 75A4's, stock R4C's,  and other old receivers which
have very poor performance in many aspects. They do well on weak signals on
relatively clear areas of the band, because the filters have less time error
delta over the passband, yet are horrible in many other aspects.)

Just be careful! Weak signal detection under one set of conditions doesn't
mean a receiver is "good" or "bad", or that someone else might not find the
ranking totally incorrect for him in another "clear channel" noise test.

The exceptional thing about the Orion is ALL of this can be corrected by the
owner. Not so with other rigs.

I'm reserving judgment until the normal bugs of having a new product are
worked out. It will take time to for TT to consider customer feedback and
make changes. Let's give them some reasonable time, before we fall in line
behind manufacturers who traditionally have ignored major problems that
impact all of us!

The setup of the TT Orion is somewhat complex and is still being worked out.
To me it looks like ALL problems are minor and easily correctable, and it
will be the best radio available once the factory gets enough feedback (and
has some time to make changes).

73 Tom



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