W3ULS wrote:
It's interesting to compare the ORION's numbers against the venerable OMNI VI.
In a QEX article (9-10/02) T. Raczek included a table showing the drop-off in
performance between measurements at 20 kHz and 5 kHz spacings for a bunch of
transceivers. The OMNI fell off 9 dB in BDR and 14 dB in IMD DR--one of the
better results. The ORION, for all practical purposes, doesn't fall off at all,
according to the new ARRL data.
On March 9, 2000 I posted to CQ-Contest (and subsequently updated
for a few other rigs) and cross-posted to this reflector a reference the
following often ignored, but I think you will agree, informative data,
which does not show the OMNI VI dropping off in close. Notice that
the Corsair was the "hero" of these rig comparisons. I have often
considered the Elecraft a simplified Corsair with electronic tuning.
It's interesting that people for so many years turned up their noses
at Corsairs and now rush to the Elecraft band wagon.
Subject: [CQ-Contest] IC756 PRO and other contesting rigs
From: 00tlzivney@bsuvc.bsu.edu (00tlzivney@bsuvc.bsu.edu)
Date: Thu Mar 9 09:35:01 2000
The March 2000 issue of RadCom has an in depth technical
review of the new ICOM IC756 PRO. I have summarized
three key technical measurements on a variety of
transceivers, all made by the same reviewer, Peter Hart,
using the same methodology. The three measurements
are the two-tone dynamic range (in a SSB bandwidth), a
reciprocal mixing measure, and the amount of transmitter
broadband noise (also in a SSB bandwidth). The rigs
are listed with the best at the top in terms of close-in
performance. The IC756 PRO ranks near the bottom.
Spacing 3k 5k 10k 15k 20k 30k
Corsair I - November 1984 - no synthesizers
DR - 90 90 90 90 90
Recip - 98 98 98 98 98
TX noise 95 95 95 95 95 95
OMNI-VI - January 1994
DR 88 88 88 88 88 88
Recip 86 86 - 96 96 96
TX noise 83 87 96 97 98 98
FT1000MP - January 1996
DR 78 82 92 103 99 98
Recip 80 86 94 99 103 108
TX noise 76 81 89 94 96 99
IC737 - September 1993
DR 74 80 88 92 94 98
Recip 90 96 104 105 107 110
TX noise 79 87 93 95 96 97
FT990 - April 1992
DR 70 78 88 92 94 96
Recip 83 87 93 97 100 105
TX noise 74 79 84 86 87 88
TS690S - November 1992
DR 67 77 87 91 93 94
Recip - - - 98 101 105
TX noise 70 77 82 85 88 88
TS930 - May 1986
DR - 77 87 - 91 92
Recip 77 83 89 - 97 101
TX noise - 79 83 - 85 88
TS940 (with Lowe modification to improve reciprocal mixing by 12db)
- May 1986
DR - 76 81 - 88 91
Recip 83 89 98 - 105 110
TX noise - 72 72 - 72 74
TS850 - October 1991
DR - 75 89 95 95 96
Recip 85 89 100 105 108 112
TX noise 75 83 90 95 96 99
IC756 - May 1997
DR 74 74 75 79 82 86
Recip 79 84 91 95 98 102
TX noise 73 80 87 91 94 97
IC756 PRO - March 2000
DR 72 73 76 82 86 90
Recip 83 86 92 96 98 101
TX noise - - - - - -
IC775DSP - January 1996
DR 72 72 78 87 91 93
Recip 90 96 100 103 106 109
TX noise 78 80 87 92 97 100
FT920 - August 1997
DR 70 72 83 95 97 96
Recip 85 90 97 101 104 108
TX noise - - - - - -
TS50S - May 1993
DR 67 69 74 80 84 92
Recip 78 84 95 - 103 104
TX noise 74 79 85 90 93 97
FT847 - August 1998
DR 65 67 78 89 96 94
Recip 76 80 90 94 97 101
TX noise 70 76 86 90 93 97
FT1000 - June 1991
DR 65 65 72 82 88 93
Recip 81 85 91 95 98 102
TX noise - 76 81 - 84 -
TS870 - April 1996
DR 58 61 73 84 94 95
Recip - - - 100 103 107
TX noise 75 80 88 91 92 93
IC781 - July 1990
DR 52 57 76 92 97 -
Recip 90 96 103 106 110 113
TX noise - 85 92 - 98 -
Notes:
DR - two-tone dynamic range on 7 MHz in SSB bandwidth
Recip - reciprocal mixing for 3dB increase in receiver noise
TX noise- dBC in 2.5kHz bandwidth
spacings refers to spacing of the two tones for dynamic range and
the offset from the carrier frequency for reciprocal mixing and
TX noise
Dates refer to issues of RadCom containing the Peter Hart review.
Rigs listed in order of decreasing dynamic range with 5 kHz spacing.
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|