[1000mp] W2VJN Comments on Roofing Filter IF Adjustment

[Pete Smith]

For what it is worth, this quietness business has always been a subject of 
some debate; there are technically competent people who argue forcefully 
that the gain redistribution accomplished by the IF mod and the later 
roofing filters may actually degrade IMD performance while improving 
MDS.  But I do wonder whether Inrad feels that the later roofing filter 
units really do offer the same improvement in MDS as the IF mod.

73, Pete N4ZR

At 03:57 PM 2/1/2005, Mike Schatzberg wrote:

>Hello Pete:
>
> >From an insertion loss point of view, permitting a significant reduction in
>IF gain setting, in menu 9-1, and thus accomplishing both the stated
>promised improvements in IMD reduction, whiskering, etc., as well as the
>unstated improvement in noise floor reduction.  The later production units,
>which may have the lower insertion loss crystal filters,  as perhaps does
>yours for all anyone knows, will function to serve as both mods ( roofing
>filter and IF amp) at once.
>
>This does not mean the earlier filters do not work.  The later ones
>apparently further improve the quietness of the receiver also.
>
>Regards,
>
>Mike
>----- Original Message -----
>From: "Pete Smith" <n4zr at contesting.com>
>To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>; "All about Yaesu
>1000mp" <1000mp at mailman.qth.net>
>Sent: Tuesday, February 01, 2005 3:37 PM
>Subject: Re: [1000mp] W2VJN Comments on Roofing Filter IF Adjustment
>
>
> > I do not understand this statement.  Do you mean late-production roofing
> > filters are better, or what?
> >
> > If the former, then I doubt George would agree with you.  I have a second
> > run roofing filter, and certainly feel it is a huge improvement in my Mark
>5.
> >
> > 73, Pete N4ZR
> >
> > At 02:52 PM 2/1/2005, Mike Schatzberg wrote:
> > >The newer crystal filters are working incredibly well, far more
>efficiently
> > >than the earliest units which were produced by Inrad.
> >
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