The 6+ in qst expanded review does 3rd order 25db down on 160m
5th 46db
and a best of: 3rd 30db down on
30m
5th 46db
Nothing to brag about here.
Steve wd0ct
----- Original Message -----
From: "John Rippey" <w3uls@3n.net>
To: <tentec@contesting.com>
Sent: Saturday, April 13, 2002 11:35 AM
Subject: [TenTec] OMNI VI Transmit IMD
> Something made me look up the January 1993 QST review of the OMNI VI and
> check its transmit IMD stats. The reviewer, Rus Healy, says (p. 67), "As
> Fig 1 shows, the transmitter's third-order IMD products are down almost 40
> dB, which is excellent for a rig with 13.8-V final-amplifier transistors."
>
> The QST review (11/00) of the FT-1000MP Mark-V says only, "The original
> 'MP did pretty well in the IMD department, with worst-case third-order
> products down about 27 dB and fifth order products down about 43 dB (this
> was on 24.95 MHz)." With regard to the Mark-V, the reviewer, Rick
> Lindquist, focuses on the Mark-V's built-in Class A amplifier for its
clean
> output. There is no mention of Class A-B results but, according to the
> graph accompanying the review, in Class A-B (i.e., normal) operation, the
> Mark-V's third-order products are 27 dB down and fifth order are 48 dB
down
> (21.250 MHz), virtually identical to the earlier 'MP's results.
>
> Yaesu's final amplifiers in both the 'MP and the Mark-V have yielded 13dB
> worse IMD performance (albeit at 200 watts) compared to the OMNI VI's
final
> amplifier, and by so doing they have met a (new to me) "doing pretty well"
> standard for third-order IMD products enunciated in the Mark-V review,
> which I take it lies somewhere between "excellent" on the one hand and
> "godawful" on the other.
>
> Note also ARRL is reporting in the May QST that the worst-case third-order
> transmit IMD number for the IC-746PRO is 25 dB down. I don't know if this
> means the IC-746PRO also has cleared the "doing pretty well" criterion.
>
>
> 73,
> John, W3ULS
>
>
>
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