[1000mp] Yaesu Bandpass Filters

[Mike Schatzberg]

Hello All:

I have had the 1.8 khz Inrad filters in my Mark V's second and third IF, and
found the combination most effective for fighting QRM, but too fatiguing for
everyday DXing.

After trying several filter combinations, I personally like the 1.8 Inrad
crystal filter in the second IF, and the Collins 2.0 mechanical filter from
Inrad in the third IF.

Perhaps this combination does not give the sharpest skirts, but the quality
is what my ear is accustomed to hearing, using the Collins 2.4 filter in the
normal slot, with its ten poles.  The Collins 2.0 filter, in the narrow
slot, has eight poles, but works very well.  A slight adjustment of the IF
Shift control counterclockwise will really make the audio sound great, even
with these narrow filters.

I find the digital filters work just fine, tracking this analog filter
combination.

I used the 1.8 filters for nearly two years before changing, and I am quite
comfortable with the Collins filter now.

I do not recall anyone discussing this possibility before, but if you select
the digital product detector option, and use some negative carrier offset
for USB, you will enjoy the combination.

Regards,

Mike Schatzberg
WB2AJI
----- Original Message ----- 
From: "Joe Subich, K4IK" <k4ik at arrl.net>
To: "'All about Yaesu 1000mp'" <1000mp at mailman.qth.net>; "'RCARIELLO'"
<RCARIELLO at si.rr.com>
Sent: Friday, October 01, 2004 10:23 AM
Subject: RE: [1000mp] Yaesu Bandpass Filters


>
> Rich,
>
> > I am trying to identify the Bandpass filters that came with
> > my FT-1000mp.
> >
> > Yaesu Type XF-8.2M-262-01
> > Yaesu Type XF-8.2M-501-03
> >
>
> The part numbers identify the filters as 2600 Hz and 500 Hz 6 dB
> bandwidth, 8.215 MHz center frequency crystal filters (Yaesu's
> "stock" SSB and CW 2nd IF filters).
>
> > After identifying the filters, I am considering to remove the
> > 2.4 K filter attached to the PC Board. I would replace it with
> > the 2 K filter Yaesu Type XF-114SN. Of course I would first have
> > to remove this filter from it's plug-in board. In the 2.4K 455
> > IF slot I would plug in the Yaesu Type XF-110SN 2K filter.  I
> > believe this would now provide a 2K bandpass when the 2.4K
> > Bandpass options are selected.
>
> You are correct ... However, I have the Yaesu XF-114SN/XF-110SN
> filter pair in the "narrow" position of my MKV and find them too
> narrow for day to day operation.
>
> > In the 2K slots I would place plug-in Inrad 1.8K Bandpass
> > filters. I believe this would now provide a 1.8K bandpass
> > when the 2K Bandpass options are selected.
>
> Again, you are correct about the effect ... but I don't know that
> there is enough difference between 2.0 and 1.8 KHz to be worth
> the effort.
>
> If you think the 2.4 KHz (cacsaded bandwidth for the Yaesu stock
> filters) is too wide, you might look at INRAD's 2100 Hz filters.
> The filter curves show 2175 +/- Hz @ 6 dB bandwidths.  It looks
> like their effective (cascaded) bandwidth will be around 2100 Hz.
>
> > In the Sub-Receiver slot I would place the 455 IF Yaesu Type
> > XF-115S 2.4K  Filter. I am not sure if this would improve
> > anything.
>
> It doesn't buy you anything over the stock ceramic filter except
> somewhat tighter skirts.  The slot is intended for a CW filter.
>
> 73,
>
>    ... Joe, K4IK
>
>
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