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[TenTec] OMNI VI filter bypassing?

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Subject: [TenTec] OMNI VI filter bypassing?
From: paulc@mediaone.net (Paul Christensen)
Date: Wed, 23 Dec 1998 10:30:41 -0500
Hi Clark,

I'm awaiting my 2.8 K filter.  From your first impression, it appears the
filter has corrected the LSB/USB passband asymmetry problem.

As you pointed out, the impetus for the change was to correct a problem on
some Omnis where the fixed BFO frequency of 9,000.400 kHz fell square on the
2.4 K filter's steep, lower skirt.  I am VERY interested in hearing the
results from your CW testing.  Unfortunately, you're just too far from me to
hear a good strong CW signal on the lower bands, where I am presently

Regarding the 6.3 MHz position: I don't have the schematic in hand, but I
presently run my Omni with nothing but a jumper between the 9 MHz wide
filter pins.  In that position, I don't believe there are any DC coupling
issues, although there may be in the 6.3 MHz position.  Without the filter
in place, I don't think that exact impedance matching is going to be too
critical.  You're right however, the ultimate solution is for George to make
a 2.8 kHz @ 6.3 MHz IF filter.

Please let us know the results of your CW testing ASAP.  Thanks Clark!

-Paul, W9AC

-----Original Message-----
From: Clark Savage Turner <turner@safety.ics.uci.edu>
To: tentec@contesting.com <tentec@contesting.com>
To: <tentec@contesting.com>
Date: Wednesday, December 23, 1998 10:08 AM
Subject: [TenTec] OMNI VI filter bypassing?

>Hello All -
>I just got my INRAD 2.8 KHz SSB filter for my OMNI 9 MHz
>IF.  It does indeed help the PBT to work a bit more to spec
>and seems to be fine.  However, with the 2.4 KHz filter in
>the 6.3 MHz IF, I cannot hear the wider audio that it passes.
>This brings me to my question: I have the 1.8 KHz option
>empty in the 6.3 MHz IF line.  Can I just run a .1 uF cap
>from hot side to hot side (to block DC) of the filter slot
>and run directly through the 6.3 MHz IF so I can hear this
>filter?  Or, should I stick in a 200 ohm resistor in series
>with the cap to keep the impedance close to specs of the
>filter that would be in there.  I would love to compare the
>sound of the model 220 in the 9 MHz spare slot against the
>new INRAD filter with the 6.3 MHz IF filter disabled, just
>to see how it looks.  I eventually want George to build us
>a matching 6.3 MHz IF filter at the 2.8 KHz width so that
>I can hear a fuller SSB signal, but till then, it would be
>good to know the difference.
>I plan to play around on CW to see how the note sounds there,
>the filter order was originally all about making the OMNI VI
>CW note sound a little better.  Anyone else get there 2.8
>filter from INRAD want to make a schedule?
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