Bill,
Thanks for the confirmation.Now I understand.
Makes sense. Here it comes from the headphones and the speaker.
Best 73 Mark Wq7X
>
> From: Bill Tippett <btippett@alum.mit.edu>
> Date: 2005/05/23 Mon PM 05:09:48 EDT
> To: tentec@contesting.com
> Subject: Re: [TenTec] My new ORION
>
>
>
> WQ7X:
> > So, I just hope that distortion of strong signals will be
> > eliminated (doesn't exist in other DSP radios).
>
> NQ5T:
> I've read with interest all of the discussion of this issue. I have yet to
> experience any case of a high level signal causing distorted output, at 9+35
> or anywhere -- but of course I haven't found a signal around here that has
> bent the S-meter yet, either, although on 75 meters at night there are some
> VERY strong signals :-)
>
> Grant, I believe the strong signal distortion problem
> began with 1.372 when AGC Threshold (the DSP's digital IF gain)
> was integrated with analog RF gain (previously set by RFGAIN).
>
> "11/30/04 Version 1.372
> - Enhanced RF GAIN control knob operation."
>
> 1.372's RFGAIN now controls both analog and digital AGC gain,
> which makes Orion's AGC much easier to use, but apparently the code
> which limits the input to the DSP has been corrupted. When any
> DSP is over-driven, very bad distortion results. The Analog AGC loop is
> supposed to protect the DSP stage from any
> signals exceeding about S9+35, but that protection has
> apparently been lost in 1.372, under certain conditions.
>
> My unit does not distort consistently, but often enough
> to be a bother. However, I like 1.372's integrated RFGAIN
> so much that I am living with 1.372 until the problem is fixed.
> One alternative to fix the distortion problem is to re-install
> 1.371, if you don't mind separately setting AGC Threshold and
> RFGAIN as before. I'm sure this problem can be fixed once the
> major revision (2.0) is completed.
>
> BTW, the first report of this noted it was only when using
> headphones (doesn't seem logical to me) but that could explain why
> some have not noticed it (if they always use the speaker). I
> never use anything but headphones so cannot comment.
>
> http://dayton.akorn.net/pipermail/orion/2004-December/000504.html
>
> 73, Bill W4ZV
>
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