[TenTec] USING ORION'S RECEIVER

[Carl Moreschi]

Sinisa,

Great document about how to adjust the Orion.  Very well done.  I have one
comment I disagree with it.  The AGC threshold adjustment on the Orion is
actually the point where DSP gain is added to a weak signal to bring the
weak signal up to the same audio level as a strong signal.  Signals below
this value are not amplified in DSP.  This is opposite all other AGC
implementations I have seen.  This is why the audio level goes down as you
increase AGC threshold.  All signals above the AGC threshold are adjusted to
produce the same aduio level.

In other receivers, signals below the AGC threshold are heard at full gain
with no AGC reduction.  This is clearly not the case in the Orion.

73,

Carl Moreschi N4PY
Franklinton, NC
----- Original Message -----
From: "Sinisa Hristov" <shristov at ptt.yu>
To: <tentec at contesting.com>
Sent: Saturday, February 28, 2004 3:59 AM
Subject: [TenTec] USING ORION'S RECEIVER


> A six-page PDF file (40 KB) titled "USING ORION'S RECEIVER"
> is available for download from my web site:
>
>   http://www.geocities.com/va3ttn
>
> Topics covered include:
>   * initial adjustments,
>   * setting the optimum RX sensitivity for the given environment,
>   * setting AGC to avoid it causing distortion to weak signals,
>   * adjusting roofing and DSP filters according to band conditions.
>
> Both the short theory and practical procedures are presented.
>
>
> 73,
>
> Sinisa  YT1NT, VA3TTN
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec