[1000mp] MP Roofing filter

[Thomas Beltran]

> Anyone used one yet besides the beta testers? I assume it goes in place of
> the front end mod.
>
 John:

Yes, it goes in place of the front-end mod.  I've had mine now for a while,
but I don't have any real test equipment.  The board it comes on has the
filter, and a small amp to make up for the insertion loss.  I notice that
the radio sounds "cleaner," and the "Shift" control has a little effect when
the filters are in the "Nor" position (indicating the narrower passband).  I
now use the Nor filter position most of the time on SSB, unless there is
interference.  I would say there is some improvement.  But, it is hard to
compare - what would work, is two Mark Vs doing A/B comparisons.

I've kept the front-end mod, and perhaps, Rob Sherwood could come out with a
relay board that would allow switching between the First IF filter and the
Front-end mod, depending upon band conditions.  Because both boards plug
into the MP in exactly the same way, a Sherwood-type switching board could
work.  I have a Drake R-4C that has his mods, and I think it makes a
terrific improvement compared to my stock R-4C.  He came out with the
selectable first IF about 25 years before the Orion.  The QST review of the
Orion sounded as if such a thing were brand new.  What would be nice, would
be selectable 4 khz., perhaps 1 khz, and the front-end mod.  Tom W6EIJ