It's interesting that the NR allegedly broke at the same time the
firmware was revised (from 1.371 to 1.372) to add linkage between RF
Gain and AGC threshold. And some folks are now finding that with v2
firmware they seem to be observing a need to once again manually
adjust AGC threshold to get NR right.
(just a curious bystander here since I don't use NR, although now I'm
tempted to go back to 1.371 and play with it a bit just to see how
"good" it was)
73,
barry N1EU
On 12/7/06, Grant Youngman <nq5t@tx.rr.com> wrote:
> > almost as many opinions as posts. If any consensus can be
> > gleaned from the posts, it is that the DSP NR does not work
> > as advertised.
>
> There remain some apparent descrepancies between the manual description and
> current algorithm operation, and probably everyone agrees one or the other
> should be fixed. Which one should be the focus is a point of discussion :-)
>
> > I really don't like to clamp down on bandwidth unless
> > absolutely necessary.
>
> That's fine. It was simply a suggestion. But it is effective.
>
> > In your statement that "If you operate CW with reasonably
> > narrow bandwidths, DSP NR is largely superfluous." I disagree
> > with you, if you are making that statement in a general
> > context.
>
> In the sense that reducing DSP bandwidth reduces the noise bandwidth, it is
> not so superfluous if you consider what NR would have to do to noise
> bandwidth to reduce noise levels further.
>
> > [makes] me wonder why someone values their time so cheaply, to be
> > spent by making such an inane comment... and why they think
> > that I value my time so cheaply that I'd care to participate
> > in their senseless blather.
>
> I find it hard to believe that a suggestion, given in good faith because
> someone, with or without several graduate degrees in EE with a PhD
> dissertation in some esoteric aspect of Signal Processing, finds it
> effective, would be considered irrelevant or snotty.
>
> > I'm a graduate EE, <snip> been in corporate management and not a
> > practicing engineer for the last 10 or 15 years, I am not as
> > qualified as many of you on this list...
>
> Many of us around here float in the same boat. And in any case, not all
> EE's are created equal, especially in these days of relatively intense
> specialization.
>
> > After calling TenTec and receiving no help, I posted here.
>
> What we don't know is how the other end of the conversation went :-)
>
> If you've read the archive then you know that NR has been a bone of
> contention since about Orion 1.371, if not before. I'd wager than the
> "ditsnbits" inbox has more subject lines that contain "NR is BROKEN" than
> any other topic. As for the add-on boxes from various vendors, I've owned
> virtually every box produced starting with W9GR (I think that's right),
> Timewave (not too bad, not always good), JPS (truly awful), Am-Com (great
> value, good on SSB, and I use it on an SX-115), GAP (unusable on CW),
> whatever. Each and every one sort-of works sometimes, and is marginal at
> best or just plain worthless sometimes. I keep hoping that someone will
> find a way to get blood out of a turnip, but that has not yet occurred, no
> matter how much one shells out for the 'hope' :-)
>
> Grant/NQ5T
>
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