Yes, I meant N-1 and N-2.
I've played with the passband, but N-2 cuts the signal too much (in my
oppinion).
N1 actually peaks the signal a bit.
.....Dave
----- Original Message -----
From: "Ken Brown" <ken.d.brown@hawaiiantel.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Wednesday, April 20, 2011 4:02 PM
Subject: Re: [TenTec] OMNI VI+ filter anomaly
> Hi Dave,
>
> My Omni VI is not a plus version, and has no F1 or F2 keys. I don't
> think that the + version does either, and I am guessing that you really
> meant to say N-1 or N-2. The rest of my response is based on that
> assumption.
> The 6.3 MHz IF, which is the IF that can be shifted in frequency
> using the PBT (Pass Band Tuning), is after the 9 MHz IF. If you are
> using a narrow filter in both the 6.3 MHz IF and the 9 MHz IF, and you
> have the PBT adjusted so the the pass bands do not coincide, there will
> not be much signal getting through. Try adjusting the PBT control for
> maximum signal strength or noise level.
> Once you have adjusted the PBT for maximum signal or noise while
> using one of the narrow 9 MHz IF filters, there will still be a small
> change in overall noise level as you switch between using one of the
> narrow 9 MHz filters and not.
> The filters you have in the narrow 9 MHz filter slots may also not
> have identical bandpass center frequencies. In that case the setting of
> the PBT control needed for maximum throughput, through both the 9 MHz IF
> and the 6.3 MHz IF, will not be identical for both N-1 and N-2.
> There is also the issue of the jumper settings used to compensate
> for the filter loss. The jumpers only give you a couple of filter loss
> compensation options. Yet there are a lot more than just two values of
> loss for the many available filters. For any particular 9 MHz IF filter
> there is always a "best" jumper setting to use, but seldom a "perfect"
> setting.
>
> DE N6KB
>
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