[1000mp] Roofing Filters

[Pete Smith]

QST's review of the roofing filter cites a 7 dB improvement in MDS with a 
Mark V, and 3 db with a regular MP, compared to the stock figure.  Doesn't 
this imply that the amplifier in the roofing filter mod accomplishes some 
or all of the same effect as the amplifier in the original IF mod?

73, Pete N4ZR

At 10:57 PM 12/25/2004, Thomas Beltran wrote:

>Winston, I haven't sold my IF mod kit yet, its been sitting here since
>August or so, when I got the roofing filter kit.  But I agree, and I think
>you'd agree, it would be nice to have both, and not have to choose between
>them.  Just knowing that Rob Sherwood has some involvement in this thing,
>I'm hoping that there might be a switching kit for the MP, like Rob's mods
>for the Drake R4C.
>
>(For those not familiar, Rob has had switched First IF roofing filters for
>about 20 years, 600 hz for CW, and 2.4 khz. USB and LSB, switched from a
>small relay control board that fits inside the radio - there is a
>replacement double-duty knob that replaces the AGC knob (which came out more
>recently), so that the larger rear knob switches the AGC positions, and the
>smaller front knob switches the filters - very elegant.  It was nice to see
>some of this 20 yr. old technology applied to the Yaesu.)  Rob has the
>results of his testing, and those old R-4Cs of bygone years make a good
>account of themselves.
>
>Since the connections for the Inrad filter and IF mod kit are exactly the
>same, it doesn't seem like such a thing would be sooo difficult [easy for me
>to say].  There is certainly a lot more room in the Yaesu, than in the
>Drake.  When I wrote to George over a year before coming out with the kit,
>raving about how well Sherwood's stuff worked, he said that he had been
>working on it, but a roofing filter of any real selectivity seemed to be
>impractical in the Yaesu, because of the high IF frequency.  But he did it,
>and maybe not a "must have" as some might say, but it works quite well.  So,
>I'm saving my IF kit, hopefully, I'll be reinstalling it with a switch kit.
>Certainly there is a business motivation also, instead of an either-or,
>every MP owner could conceiveable own (and use) both.  Sign me, "holding out
>for the switching kit."  Tom W6EIJ
>
>
>
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