[TenTec] FS: Omni VI +....excellent

[Paul Christensen]

> There is NO electrical/mechanical difference between the radios other than
> the front panel of the option 3 rig does not include the word "plus."

This is essentially correct.  However, there are some differences between
the two radios:

1) If I'm not mistaken, the Omni Six (and all factory upgrade versions 1-3)
use a crystal oven for the reference oscillator.  The Omni Six Plus uses a
TCXO and was not incorporated into upgrades 1-3.  (someone keep me honest
here);

2) The Omni Six Plus uses different 9MHz BFO and Control Boards.  In the Six
Plus, the LSB crystal is shifted in CW.  The Omni Six uses the USB crystal
and requires more shift (~2.6 kHz versus 400 Hz) than the Omni Six Plus.
Presumably, this was effectuated to assist in the so-called "micro-chirp"
problem.  However, my experience is that although this was a step in the
right direction, better BFO crystals greatly help in reducing and/or
eliminating the microchirp - particularly if the 2.4 K @ 9 MHz filter is
bypassed in CW mode OR the INRAD 2.8K @ 9 MHz filters are used.

There are likely other subtle differences between the two radios -- but
these two stick out in my mind.

73,

-Paul, W9AC