I have a different approach.... for those who are hearing impaired; I
recently purchased a pair of SIEMENS CENTRA Hearing "Aids" and had the
audiologist program them using the audio response curves of Heil Sounds HC-4
and HC-5 microphones. For using a headset while DXing, and the HC-5 curves
were used for listening to the the radio's speaker. See
http://www.heilsound.com/amateur/hcelements.htm for the information on the
microphone specs and
http://www.siemens-hearing.com/hearing_aids/hearing_aids/centra.aspx?w=c for
the hearing aid specs. By the way a pair of the CENTRA hearing aids will
cost more than your new ORION II... but "you can't work'em if you can't
hear'em"!
Best regards,
Gary - AB9M
CSM(r) G.L.Huber
9679 Heron Bay Road
Bloomington, Illinois 61704
(309)662-0604
www.csm-gh.com
csm-gh@www.csm-gh.com
gary.huber@us.army.mil
ab9m@arrl.net
former National Webmaster for The Society of the Fifth Division
www.societyofthefifthdivision.com
www.csm-gh.com/75thRepoDepo.htm
----- Original Message -----
From: "Kim Elmore" <cw_de_n5op@sbcglobal.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, December 04, 2006 9:51 PM
Subject: Re: [TenTec] Noise Reduction Setting
> Honestly, I don't think there is a significant problem.
>
> Having fancied myself very picky about audio (I'm an amateur
> violinist and was a borderline audiophile -- or audiophool -- in the
> distant past), I just did a careful listen on some 40 m CW with both
> the speaker and good headphones.
>
> I have all the roofing filters installed, set for auto selection and
> my CW pitch is 600 Hz. RF Gain is 100, preamp off, binaural rx
> disabled, and sweep display both on and off. At bandwidths of less
> than about 1240 Hz, all CW signals are silky smooth. At bandwidths
> greater than 1240 Hz, I begin to detect some filter-imposed
> artifacts. The effect is dependent upon the filter setting: the more
> aggressive the filter setting, the more apparent the effect. Even so,
> I consider it minor. What I hear sounds a bit like the noise around
> the signal, but superimposed on the signal.
>
> However, at bandwidths less than about 1240 Hz, everything is simply
> silky smooth. I tend to run my bandwidth at 600 Hz. Yes, yes, I know:
> the 1000 Hz filter may be a better choice from a rx performance
> standpoint, but I like the "sound" at 600 Hz bandwidth.
>
> I tried everything again with binaural rx enabled and found myself a
> bit more able to detect the DSP artifacts, but I also became
> convinced that at higher RF gain settings, the effect seemed to
> disappear (I find myself more able to hear noise in stereo than in
> mono. For me, stereo noise tends to have the aural effect of physical
> width -- this may not be true for everyone).
>
> When I turn down the RF gain and crank the audio gain wide open
> (essentially using the RF Gain as the volume control) I can detect
> the superimposed noise at NR settings above about 5 at 600 Hz
> bandwidth. This effect vanishes when the bandwidth is set to ~400 Hz
> or less. That said, at such RF Gain settings I see no reason to use
> any NR because everything is pretty quiet.
>
> So there you have it: while I could detect some DSP NR artifacts
> under certain conditions, those conditions are currently outside of
> my operating envelope. I don't think the "problem" is significant.
>
> Kim Elmore, N5OP
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