Hi folks -
I'm aiming this comment/question to Carl, but would like to share it
with all. Carl has the benefit of owning a truly great TenTec DSP rig
which he commented about yesterday as being the best receiver he's had.
With that in mind I'd like to share some somewhat confusing observations
and see if Carl has had similar experiences. Carl also still has, I
believe, an OMNI V.9 (I could be wrong).
After operating the 756PRO for a few weeks, I fired up my OMNI next to
it last night. A/B testing is tuff with these rigs, but I THINK the
following is about right (hard to know if I'm tricking myself:
1) - The OMNI has a smoother more pleasent sound to it's cw; the 756 has
a slighly more "percussive" sound to it. Normally not a huge issue but
see number two.
2) - In high noise conditions the 756PRO seems to have a few pops and
crackles associated with keying. The OMNI V.9 does not. I believe this
may have something to do with AGC but I'm no techno wizard. A small
percentage of the time it can be a bit quite annoying. It's possible it
could be from RFI - but I'm still checking this out.
3) - If you want to tune out background noise by turning back the RF,
you have a greater range and sensitivity to do this on the OMNI. The
756 has a much shorter range before the RF gain completely hides the
signal as well as background noise.
4) - The 756 seems to be able to hear weaker signals a bit better.
5) - When there are a number of signals close together, the 756 seems to
have a harder time sorting them out so that you just hear one. Part of
this is getting used to being willing to use its tighter filters - so
that for instance you might have the OMNI at 250 and the 756 at 150. It
also might be that the 756 is hearing more signals than the OMNI - since
sometimes I cannot locate these other signals on the OMNI. This is an
area where it gets confusing. It is a no-mans land between understanding
the noise floor, the best way to use DSP controls, selectivity, etc etc.
I would be interested in hearing Carl's experiences and observations as
he went from crystals to DSP. Did he have similar questions and
solutions?
As I say, when you try to be objective - and are not depending on lab
tests - these are two different beasts and hard to compare. I thought
you all might find this interesting and, if Carl has time to respond,
his comments will likely be much more interesting!
Have a good day all!
73/Tim Logan KB7OEX
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