[TenTec] NR - Fact or Fiction?

[Mary Ann Higgins]

Bill I also agree with you about NR. 2.055. Best by far I've seen fer
SSB. All or nothing never fer me since I only operate SSB. But when i
tried NR on CW 1.371 was very effective. Kewood has NR1 FER SSB & NR2
FER CW on 870 and 2000. Maybe TT could
offer a choice in menus. Bill I'm not a big anything but 2.055 does it fer me.

On 3/2/06, Bill Tippett <btippett at alum.mit.edu> wrote:
> K4IA wrote:
>
>  > However, the software still ain't right after 2 1/2 years.
>
>          Buck I cannot argue with you.  Unfortunately it may
> be the case that it is never completely "right".  That
> said, the other benefits of Orion far outweigh most of
> the firmware issues for my operating.  I operate contests
> seriously and simply would not tolerate frequent crashes
> (which don't happen often in my usage and experience).
>
>  > I am a hold-out for the Noise Reduction of 1.371 - it stopped working in
> 1.372 and hasn't been right since.  NR in Ver2 just distorts and there are
> plenty of posts still complaining about problems with the audio and
> other issues
> in 2.055.  As good as TT is, the software is a serious shortcoming and  there
> is nothing wrong with admitting it.
>
>          This brings up a discussion we had on the beta
> list and maybe it's time to make it public here.  IMHO,
> NR on any rig (or outboard DSP of any flavor) is little more
> than marketing hype.  Think about how NR actually works.  It
> automatically builds a narrow DSP filter around the signal
> of interest.  Guess what, you can do exactly the same by
> directly turning Orion's BW knob to 100 Hz!  There is no magic
> in DSP of any flavor.  They work by simply reducing noise
> bandwidth to improve the S/N ratio.  There is NOT some
> magical algorithm that extracts the signal from noise.  This
> is the way all DSP's work including Linrad (the Linux-based
> software EME guys use).  Don't get me started on JT65 which
> actually cheats by using data exchanged by means other than
> on-the-air in real-time...I can also find creative ways to
> cheat via the Internet if I got a thrill out of that.
>
>          In one of the V2 beta releases, one of the team felt
> that version 2.XXX's NR was a major breakthrough in S/N
> (Minimum Discernible Signal for a given noise bandwidth).
> ARRL chooses 500 Hz BW for consistency across all rigs they
> test but you can compare MDS at other BW's as well.  After
> someone made the MDS comparison between the two firmware
> versions in question, they discovered that MDS was exactly the
> same!  The problem is that NR compensates the gain to adjust
> for the lower noise bandwidth, so you can't really do an A
> vs B comparison instantly.  The gain change fools our brain
> into thinking it is helping, but when you make the actual S/N
> measurement (MDS) you discover NR actually does nothing that
> simply reducing Orion's bandwidth will not do as well (and
> much faster to boot).
>
>          I work lots of weak DX signals on 160m and also
> hold the current record (27 uW) for copying the N2XE weak
> signal beacon on 80m.  FWIW I never use NR.
>
>                                          73,  Bill  W4ZV
>
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