From some of the postings , I think there was some misinterpretation of
either the question or the actual series of Omni's.
There was both an Omni-A, series a, and an Omni-D, series a.
However, in reality, when they first came out, Ten-Tec didn't call them a
version "a" - since at that time they probably didn't know if/when there
would be later versions. In any event, we can call them that, since the
next version was called a "b".
The poster already stated that he has an Omni-D, series a, thus he doesn't
need the counter assembly for the digital readout.
The series "a" was just the first version released for both the Omni-A
(analog dial) and the Omni-D, digital dial.
The early series "a" has the following major differences:
1. Instead of a notch filter, there is a front panel squelch control.
Later versions eliminated the squelch control and used the same knob
position for a notch filter.
2. The offset tuning only has a control for receive offset tuning. The
later versions added
a control switch enabling transmitter offset tuning.
3. NO optional crystal filters were available or could be installed.
Instead the 3 position audio CW filter, carried over from the Triton units,
was standard. The later "b" version added an optional filter PCB and
changed the audio filter select knob to control both audio and xtal filters
- a somewhat awkward arrangement. The "c" (or just OMNI-C - if you prefer)
version added toggle switches allowing totally separate control for either
audio or xtal filtering.
No WARC band operation was possible for the "a" version. There was a 10MHz
position solely for WWV receive. On that switch position, all passband
filter components for transmitter operation were left out,so it's not just
a matter of adding a crystal. There was an "aux" position on the band
switch but no filter components were intalled for either transmit or
receive. It was basically just a blank switch position. Later, component
kits were offered by Ten-Tec to enable 10MHz transmit and to convert the
aux for 12 mtrs. Those kits are no longer available.
There was also a kit to convert the "a" to a "b" version. This kit
consisted of a front panel overlay
plate that fit over the squelch and filter controls, changing the labeling
to notch and crystal filtering. Plus the kit came with necessary switches
and optional filter PCB. I doubt that any are still available..
Thus you can find sort of "intermediate" models that have had that front
panel kit installed, adding some of the "b" modifications.
There are other minor differences between the series but the above were the
most important or noticeable.
The above info comes from my experiences owning these rigs and from the
fact that I still have the original factory sales literature for the
Omni-A/D, series "a".
As to whether or not you should try to add any of the mods, I wouldn't.
The original audio CW fitler isn't bad for casual to moderate CW operating
and the notch filter is hardly a necessity. I never had much use for
transmitter offset tuning. Just my $.02.
73,
Doug/WA1TUT
>I find myself the surprised owner of
>an OMNI D 546 Series A rig, courtesy
>of a ham who gave it a non-ham buddy
>of mine who then gave it to me.
>I got the manual and a power cord from Ten-Tec.
>Since there was at least a Series B,
>I assume that there are mods to Series A.
>Any suggestions on what are the
>"low hanging fruit" mods and where
>to find info on them?
>Thanks.
>Cheers,
>Ron McConnell
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