[1000mp] ARRL data - 1 kHz IMD and BDR performance

[Scott Manthe]

If you consult the Peter Hart reviews from the RSGB,  you'll find the
original MP isn't really all that much better than the Mark V, except for
blocking dynamic range, which many people would say isn't really the most
important indicator of receiver performance.

As far as the difference in performance between the Mark V and the Field,
according to Yaesu, and I believe this has been verified by others, the Mark
V and the Field have exactly the same receiver, so the variance is
interesting, but possibly not all that important.

According to Chip Margelli, the variation between the two models (the Field
and the original Mark V) in the ARRL review could be explained by a few dB
extra gain added somewhere in the RX chain of the Field that was tested
during the factory alignment. So, I guess you could say it's either a
statistical variation or bad Q.C. One of my biggest problems with the ARRL
lab tests is that so many people cite them, without understanding the
numbers (including me) or the possibility of fairly large variances between
individual rigs of the same model. Certainly, a better way to test rigs
would be to test two of the same model and publish the results from both
rigs, or average the results. And comparisons betweens models from different
manufacturers is also difficult because 5 dB difference between rigs is
really meaningless, because that amount of difference could be explained by
something like component tolerances. The best you can do with  the review
numbers is get a general idea of a rigs performance, and even that can be
difficult, because all of those numbers- 2TTOIMD, BDR, 2OI and TOI-
interact.

Per W4ZV comments regarding Icom's claims for the ProII vs. the original
Pro: I've talked to many fairly serious DXers (Honor Roll guys) who've owned
both the Pro and the ProII (and a couple who were on expeditions with the
either the Pro, ProII or both to some islands in the Pacific) about the
apparent discrepancies in the ARRL measured RX performance vs. the Icom
claims and to a person, everyone who's owned both the Pro and ProII said the
ProII was the superior performer. This makes absolutely no sense whatsoever
to me, especially given some of the extraordinarily mediocre numbers posted
by the ProII in the ARRL lab tests, but apparently it somehow works.

73,
Scott, W9AL

----- Original Message ----- 
From: "Bill Tippett" <btippett@alum.mit.edu>
To: <1000mp@mailman.qth.net>
Sent: Thursday, January 29, 2004 6:15 PM
Subject: Re: [1000mp] ARRL data - 1 kHz IMD and BDR performance


> AJ2W wrote:
>  >Too bad the FT-1000D was not included in the tests.
> Also, amazing how the original 1000MP is much better than
> the newer MK V or Field models.
>
>          I agree with both comments Larry.  Regarding the MP vs
> Mark V vs Field, one inconsistency is that the original MP was
> tested by a different person than KC1SX.  However that does
> not explain the differences between the Mark V and Field.
> Another issue could simply be production variations due to
> this being a sample of one for each product.  However the
> -9 dB variation in IMD between successive models looks like
> a more significant difference than can could explained by
> statistical variation.
>
>                                          73,  Bill  W4ZV
>
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