Paragon/Omni VI (and other rig) differences
Thu, 28 Mar 1996 08:28:51 -0500 (EST)

My understanding is that the Paragon line has built in FM which results
in a broader roofing filter while with the Omni you go right into the narrow
first IF filter.  By the way, that is a big problem with the Rice boxes -
they all have broad roofing filters which results in dramatically worse
3rd order intermod - that's why QST uses 20 and 50 kHz tone spacings in
their lab reports - the Rice boxes fold up with reasonable tone spacings
such as 2 or 5 kHz.  The RSGB reviews in Radio Communications have used
close together spacings for years, and the Omni and Corsair have been
measured to be head and shoulders above all the competition in terms of
close-in stuff.  Of course, contester would apparently be concerned with
close in stuff.  

Now QST is getting on the 2nd order bandwagon, where TenTec doesn't 
measure up quite as well as the Rice Boxes.   This is because of the
differences in front-end filtering.  I suspect (don't have info) that
the Paragon would be better because the up-conversion for broadband
coverage tends to require better front-end filtering to suppress spurs.
2nd order intermod is not important if you use monoband antennas and/or
front-end filters (like ICE) which contesters routinely use.  On the
other hand, 3rd order intermode cannot be cured by better antennas or
front-end filters.

By the way, the close-in problems were the reason that the Sherwood
mods for the R4C were so popular.

Terry Zivney, N4TZ/9