[Orion] Truth in Advertising...Icom Style (again)

[Bill Tippett <btippett@alum.mit.edu>]

        Both N1EU and W4PA noticed that the
minus signs were omitted in my quote from
ARRL's TOI measurements of the PROIII.
That is apparently a problem somewhere in
E-mail progams since I did send the correct
numbers and they do appear in the archives
correctly.

http://dayton.akorn.net/pipermail/orion/2005-January/000597.html

        At any rate, to clear up any confusion,
here it is again with MINUS inserted instead
of "-", and PLUS inserted instead of "+".

                        73,  Bill  W4ZV

March 2005 QST Product Review:

http://www.arrl.org/members-only/prodrev/pdf/pr0503.pdf

******************************************
ICOM?s advertising for the PROIII
trumpets what it calls ?PLUS 30 dBm-class
third-order intercept point? performance
on 20 meters. This would put it on a par
with some of the best receivers we?ve ever
run through the Lab. Third-order intercept
(TOI) is a number that many like to
use as an all-in-one performance benchmark,
since its value derives both from
the receiver?s sensitivity and its front-end
selectivity (specifically, two-tone, third-
order IMD dynamic range). The more
positive the number, the better, and TOI
figures can also be negative.

Although the PROIII Instruction
Manual doesn?t specify the advertised TOI
number, an ICOM Product Guide, originally
in Japanese, spells out the measurement
conditions: 100 kHz spacing (wider
than our Lab?s widest 20 kHz spacing measurement),
preamps off and a 2.4 kHz filter
bandwidth.

Nonetheless, under the least stringent
measurement standard the ARRL Lab
uses, the PROII came pretty close to meeting
the PLUS 30 dBm mark. At 20 kHz spacing,
we calculated the TOI at PLUS 25 dBm
on 14 MHz with both preamplifiers turned
off. That works out to a slightly less than
a 5 dBm improvement over the PROII, all
other things being equal.

Under the same conditions at 5 kHz
spacing?something much more akin
to real-world amateur conditions (and
this time well within the passband of the
receiver?s 15 kHz roofing filter)?we
determined the PROIII?s TOI to be
MINUS 17 dBm, 1.8 dB better than the MINUS
18.8 dBm we calculated for its predecessor."
***********************************************

Whoopee...a whole 1.8 dB improvement
at 5 kHz for another $800?  And (er......
ahem)...Orion's IP3 was measured by
ARRL at 5 kHz to be PLUS 22.1 dBm, a mere
39.1 dB better (for just $300 more) but still
below Icom's touted spec of PLUS 30 dBm.  :-)

At least ARRL is getting a little tougher
than I've seen previously (last paragraph's
"real-world" comment).  Some day they
may actually have the guts to call a spade
a spade in their reviews.  Naah...not likely
as long as Icom keeps buying all those
advertising pages in QST.

                        73,  Bill  W4ZV

P.S.  I finally broke the code...PRO stands
for PRO-fessional B.S.

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