[1000mp] 1000MP-MV Filter choice

Thu, 28 Mar 2002 09:17:08 -0500

I UNSOLDERED the stock Yaesu 500 in my MP and replaced it with the
INRAD 400. I got the INRAD 400 to match in the 455 IF.

Having the combo also means that the skirts are matched in the points
where they dive and have a flat(er) pass band than a miscellaneous
combination. This means that the skirts are sharper and more "sudden"
in their effect.

What is really neat, though, using the 400's on a run frequency in a
contest, is having an S9+30 signal up or down 500 Hz be simply
INAUDIBLE (assumes no key klix). The miscellaneous combos will not
deliver that.

Helps a lot in a contest trying to copy a QRP signal from EU on 40
using a wet-noodle class antenna (or a 100w signal using a dry-noodle
class antenna).

With the pair, the passband shift can have enormous rejection effect
with small adjustments.

Only thing around that is sharper is a pair of INRAD 250's, which I
also have. Have to make sure that I don't go looking for run
frequencies with the 250's on. You will NOT hear stations up and down
that will have NO chance of NOT hearing YOU if you start a CQ there.

If everyone could get on frequency when they called and everyone had
cascaded INRAD 250's, we could get 240 calling stations below 7060.
Imagine taking three hours to work everybody on 40 S&P at the
beginning of SS and still having a rate of 80/hr ...

(as in dream on...)

73, Guy.

----- Original Message -----
From: "Jim Harvey" <[email protected]>
To: <[email protected]>
Sent: Thursday, March 28, 2002 8:35 AM
Subject: Re: [1000mp] 1000MP-MV Filter choice

> .> Be aware that, in the MP, two 2nd IF filters--500 and 2400
Hz--are wired
> in,
> > and must be desoldered to be replaced. I am not sure if the Mk V
is the
> > same. Desoldering requires detachment of many connectors, and
removal of
> the
> > circuit board, and is not a quick, easy operation. If you are not
> > technically adept at such work, either have it done for you, or
leave the
> > filters be and add only the snap-in filters.
> >
> > You can move the 500 Hz Collins mechanical filter from the main
3rd IF to
> > the sub-receiver 2nd IF and install a 400 Hz INRAD in its place.
The
> > combination of the wired-in 500 Hz in the 2nd IF and the sharp
INRAD in
> the
> > 3rd IF should suffice--the 400 Hz filter then essentially defines
the
> > passband, while both define the stopband. If you need to spend
more money,
> > add a 250 Hz CW INRAD filter to the 3rd IF band, and/or a pair of
2.0 kHz
> or
> > 1.8 kHz INRADs for SSB.
> >
> > In my case, I added a pair of 2.0 kHz INRAD filters for SSB, moved
the
> > mechanical filter to the sub-RX, and added 400 and 250 Hz 3rd IF
filters
> for
> > CW and RTTY.
> >
> >
> > Garry, NI6T
>
>
> I have done exactly what Gary has done, except I added INRAD 1.8's
instead
> of 2.0's to my MK V. The factory wired in 500 in combo with the
INRAD 400
> works very well and I just use the INRAD 250 when the going gets
really
> rough. The INRAD 1.8's are super. The first few minutes of using
them takes
> some getting used to but once you adjust to the sound they are
great. I use
> them 100% of the time in contests but just use the stock filters
when
> ragchewing on a quiet band.
>
> Jim  N0AV
>
> > > -----Original Message-----
> > > From: [email protected]
> > > [mailto:[email protected]]On Behalf Of Thomas Rudolph
> > > Sent: Wednesday, March 27, 2002 12:46
> > > To: [email protected]
> > > Subject: Re: [1000mp] 1000MP-MV Filter choice
> > >
> > >
> > > Hello again,
> > >
> > > please let me answer my question myself ;-)
> > >
> > > I digged a little bit more in the list archives and the web, and
IMHO
> the
> > > best way is to use complete
> > > INRAD filter pairs. So I think I'll use 1.8k and 400Hz pairs +
> > > 70MHz IF mod
> > > , and that's it.
> > >
> > > Of course I'm still interested in further experiences and hints.
> > >
> > > 73 de DK3DUA
> > > Thomas
> > >
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