Bill,
Yes, I noticed the filter was closer to the selected BW with higher BW's.
Mark
----- Original Message -----
From: "Bill Tippett" <btippett@alum.mit.edu>
To: <tentec@contesting.com>
Sent: Thursday, August 07, 2003 7:12 AM
Subject: [TenTec] New Orion Questions
> Mark wrote:
>
> 1) Filter Shape: From the discussion that Doug Smith gave at last year's
TT
> hamfest, I thought that the filter shapes would be adjustable, something
> like Icom's sharp vs. soft filters. I find no mention of that in the
manual,
> and there doesn't see any way to adjust that. I've also noticed that the
> filters seem somewhat wider that similar filters in the RX340. When I set
> the RX340 filter to 100 Hz and run the audio through a computer program
with
> a waterfall display, I see a black background except for a 100 Hz wide
> bright spot at the filter location. With the Orion, the bright spot is
about
> 200 Hz wide with a 100 Hz filter selected
>
> Your results are consistent with what N4PY measured
> previously:
>
> http://dayton.akorn.net/pipermail/tentec/2003-May/033783.html
>
> You'll notice that shape factor is automatically widened as
> bandwidth decreases which I believe is done intentionally to
> reduce ringing. I've also asked TenTec about the bandwidth
> discrepancy at 100 Hz since it has been measured by various
> people from 150-175 Hz. This could be a firmware revision if
> it is not behaving correctly. Most of the other 6 dB bandwidths
> N4PY measured appear to closer to expected results.
>
> 73, Bill W4ZV
>
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