[1000mp] W2VJN Comments on Roofing Filter IF Adjustment

[Rick Moskovits]

Hi Mike, I would sure appreciate a look at that data also. thanks, Rick ve1rnm

Mike Schatzberg wrote:

> Hello Pete:
>
> Well, comparison testing has already been done, and published, on the before
> and after results of the Inrad mod,
> with adjustments having been made in the IF gain menu to equalize the S
> meter reading after the mod.  You probably
> have seen the QST review, but I think this review made with the reduction to
> the IF gain in menu 9-1 is more real world.
>
> If you are interested in the data, published by Peter Hart, G3SJX, a
> reviewer for RadCom, the RSGB
> publication, I would be please to provide that information off list.
>
> His data confirms what has been posted here in the past.
>
> Regards,
>
> Mike Schatzberg
> WB2AJI
> ----- 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 4:53 PM
> Subject: Re: [1000mp] W2VJN Comments on Roofing Filter IF Adjustment
>
> > 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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