[TenTec] Omni-6+ RX audio / EQ?

[Robert & Linda McGraw K4TAX]

Actually the DSP is in the audio path AFTER the product detector.  By
picking off audio at the product detector hence pre-DSP then the widest
response is available.  The response is limited primarily by 2 factors.  The
Low Frequency limit by the placement of the carrier on the filter slope and
the High Frequency by the filter bandwidth.

Regarding INRAD 2.8 KHz filter vs. Tentec 2.4 KHz filter the INRAD will
sound slightly better because it is wider.

73
Bob K4TAX

----- Original Message -----
From: <al_lorona@agilent.com>
To: <lmmarch@visuallink.com>; <tentec@contesting.com>
Sent: Monday, March 25, 2002 12:53 PM
Subject: RE: [TenTec] Omni-6+ RX audio / EQ?


> >
> > Is it possible to widen the receive audio in the Omni-6+
> > beyond 2.4 kHz?
> > Has anyone added an EQ to the Omni?   What type?  Thanks and
> > 73,  Mike
>
> Hi, Mike,
>
> The suggestions so far put forth will all work, but you will very quickly
> hit a limit on the receive bandwidth on the Omni VI which is caused by the
> DSP codec always being in the receive path. The DSP is always filtering
the
> received audio, even when you have noise reduction off.
>
> In particular, you will find that no matter what you do to your filters'
> bandwidth or picking off audio directly from the product detector, you
will
> not hear below about 200 Hz, nor above about 2800 Hz (I am not sure about
> the exact upper frequency limit). To extend receive bandwidth outside this
> bandwidth, you would have to bypass the DSP circuit. As soon as you do
this,
> you will have lost DSP NR, LP filtering and auto notch filter and will
have
> seriously degraded the capability of the receiver.
>
> Someone brought up signal-to-noise ratio. The S/N ratio will actually be
> degraded by the mods mentioned above, as is the case whenever you widen
the
> bandwidth of a system.
>
> Regards,
>
> Al  W6LX
>
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