[TenTec] Omni 6 sensitivity
Duane - N9DG
n9dg at yahoo.com
Sun Dec 19 12:34:45 EST 2004
I concur with Steve's assessment regarding the SSB rag
chewing case. The Pegasus/Jupiter are probably the two
most pleasant SSB rag chewing radios that there are.
They are not however the best there is when comes to
digging really weak signal out of the noise or for use
on a crowded band. Even less so if you've made the IF
gain full clockwise tweak. The Corsair design is very
clean/quiet design until you get to its audio stages;
there it really begins to show its weaknesses. The
audio filtering op amps and other audio components are
a rather noisy, the Pegasus/Jupiter are much cleaner
and have much less audio distortion.
So it is the relative strengths and weaknesses of both
the Corsair and Pegasus that inspired my DSP IF
experiment with the Corsair II. My initial results
have been very encouraging. More to follow on that
when I get some control issues with the SDR-1000
squared away (I also have some other slightly
different ideas along that same vein in the works too
;)).
Having never used an Omni VI I can't comment about
them. I do believe though that they have a better
(cleaner) audio final amp than the Corsair and other
earlier TT radios with National Semiconductor LM38x
series audio amps (can anybody confirm this for me?).
I also agree with the assessment of the Icom IC-765
posted earlier, it is simply not a pleasant radio to
listen to, and it suffers badly from audio IMD
distortions. I've tried the various AGC mods for it to
lessen that characteristic with little improvement. So
not sure if my 765 have some genuine component problem
or if they are all that way. I suspect it's some of
both. Its main redeeming qualities are that it can
hear very well on LW frequencies bellow 500 kHz and
its pleasant "touchy-feely" ergonomics.
Duane
N9DG
--- Steve N4LQ <n4lq at iglou.com> wrote:
> The Pegasus is going to be easier on your ears than
> almost anything due to
> it's flat audio response, lack of crystal filters
> and DSP with gentle
> slopes. If you really want the superior selectivity
> of the Omni VI then you
> need to get one with option 3 and fill up the extra
> filter slots. using the
> noise reduction feature on cw will also help your
> ears some. For SSB, you
> will be dissapointed in the Omni VI when comparing
> it with the Pegasus (FOR
> AUDIO QUALITY). So keep Peggy around.
> Steve N4LQ
> ----- Original Message -----
> From: "denton" <denton at oregontrail.net>
> To: <tentec at contesting.com>
> Sent: Sunday, December 19, 2004 11:04 AM
> Subject: Re: [TenTec] Omni 6 sensitivity
>
>
> > Ok Steve...here is my situation...
> > I have an old Corsiar II that I am using for
> casual listening with a 500
> > hrz cw filter..
> > I currently use a Pegasus for psk mostly, but I
> notice it sounds better to
> > my poor ears ( I wear hearing aids in both ears)
> than the Corasir II does.
> > I hardly work any ssb at all, just some digitial
> modes...
> > Ten Tec has used Omni VI's comming in all the time
> these days, upgrading
> > to the new Orion I assume.
> > I am tempted to pick up one of those..but which
> one?? What is the
> > advantage of the Omni VI, same with option 2 and
> same with option 3??
> > Thanks in advance...
> > ----- Original Message -----
> > From: "Steve N4LQ" <n4lq at iglou.com>
> > To: <tentec at contesting.com>
> > Sent: Sunday, December 19, 2004 7:33 AM
> > Subject: Re: [TenTec] Omni 6 sensitivity
> >
> >
> >> The Corsair II would drive you nuts in that
> situation. It's audio derived
> >> AGC would pop your eardrums on the stong signals
> so you reduce the RF
> >> gain then you can't hear the weak one's while the
> Omni VI's AGC is the
> >> smoothest one around. No comparison.
> >>
> >> Steve N4LQ
> >> ----- Original Message -----
> >> From: "denton" <denton at oregontrail.net>
> >> To: <wf2u at starband.net>; <tentec at contesting.com>
> >> Sent: Sunday, December 19, 2004 10:25 AM
> >> Subject: Re: [TenTec] Omni 6 sensitivity
> >>
> >>
> >>> Wonder how an Omni VI compares to a Corasir II
> in similar circumstances?
> >>> thanks de Denton WB7TDG
> >>> ----- Original Message -----
> >>> From: "WF2U" <wf2u at starband.net>
> >>> To: <tentec at contesting.com>
> >>> Sent: Sunday, December 19, 2004 6:37 AM
> >>> Subject: RE: [TenTec] Omni 6 sensitivity
> >>>
> >>>
> >>>>I recently got rid of an Icom 756 in favor of
> the Omni VI Opt.3.
> >>>> Side-by-side comparison showed that the Omni VI
> has a definite edge in
> >>>> weak-signal reception. The difference may be
> attributable to lower
> >>>> phase
> >>>> noise in the Omni VI. The 756 DSP wasn't up to
> snuff clarifying mushy,
> >>>> noisy
> >>>> signals. The Omni VI DSP seems to work better.
> The IC-756 could never
> >>>> hear
> >>>> weak signals in the "holes" in between strong
> stations, where the Omni
> >>>> VI
> >>>> picks up some nice activity.
> >>>>
> >>>> The PBT is different - in the Omni VI you can
> lose the station if you
> >>>> don't
> >>>> retune the frequency when the station gets out
> of the passband. In the
> >>>> Icom
> >>>> radios (I also had an Icom 740) passband tuning
> doesn't shift the
> >>>> center
> >>>> frequency.
> >>>>
> >>>> In fact, my Omni-C beats the IC-756 in
> weak-signal work, except the
> >>>> lack of
> >>>> PBT makes it harder to dig out weak signals in
> between strong stations.
> >>>>
> >>>> 73, Meir WF2U
> >>>> Landrum, SC
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: tentec-bounces at contesting.com
> >>>>> [mailto:tentec-bounces at contesting.com]On
> Behalf Of DennisKT5D at aol.com
> >>>>> Sent: Sunday, December 19, 2004 5:19 AM
> >>>>> To: tentec at contesting.com
> >>>>> Subject: Re: [TenTec] Omni 6 sensitivity
> >>>>>
> >>>>>
> >>>>> I had an Icom-765 for awhile which sported
> a very good
> >>>>> receiver comlete
> >>>>> with all the filters for cw work. It had the
> PBT and IF shift
> >>>>> mods done as well.
> >>>>> I sat it down beside the Omni 6+ and did some
> testing. Ambient
> >>>>> noise level on
> >>>>> both was almost identical with perhaps the
> edge to the 765. At
> >>>>> the time the
> >>>>> 765 was matching up with some plans I had for
> reconfiguring the
> >>>>> shack so I was
> >>>>> about to decide to sell the Omni 6+. Then the
> CQ WW CW DX contest
> >>>>> came along.
> >>>>> After A/B comparison during the contest, I
> abruptly changed my mind
> >>>>> about
> >>>>> reconfiguring the shack and selling the Omni.
> >>>>> What I discovered was this. I could tune
> between two strong US
> >>>>> stations a
> >>>>> couple of kHz's apart with the Omni and copy a
> weak DX station, 3 to 4
> >>>>> s-units, easily. Switching to the 765, I
> absolutely could not
> >>>>> hear the weak DX
> >>>>> station. All I heard was an elevated noise
> floor due to the close
> >>>>> in strong US
> >>>>> stations. Clearly, to my ears the Omni is the
> superior contest
> >>>>> rig of the two. The
> >>>>> 765 could hear as well as the Omni in
> non-contest conditions so
> >>>>> sensitivity
> >>>>> was not an issue. Both radios exhibited the
> high pitched hiss on
> >>>>> white noise
> >>>>> but again, the 765 wasn't quite as bad as the
> Omni. The
> >>>>> selectivity was what
> >>>>> really separated the two radios in contest
> performance.
> >>>>> If your radio doesn't seem to be as
> sensitivity as it should
> >>>>> be perhaps
> >>>>> there is a problem with it. The Omni's
> reputation is well earned
> >>>>> here and the
> >>>>> 765 is gone.
> >>>>>
> >>>>>
> >>>>>
> _______________________________________________
> >>>>> TenTec mailing list
> >>>>> TenTec at contesting.com
> >>>>>
> http://lists.contesting.com/mailman/listinfo/tentec
> >>>>>
> >>>>
> >>>> _______________________________________________
> >>>> TenTec mailing list
> >>>> TenTec at contesting.com
> >>>>
> http://lists.contesting.com/mailman/listinfo/tentec
> >>>>
> >>>>
> >>>
> >>>
> >>> _______________________________________________
> >>> TenTec mailing list
> >>> TenTec at contesting.com
> >>>
> http://lists.contesting.com/mailman/listinfo/tentec
> >>>
> >>
> >> _______________________________________________
> >> TenTec mailing list
> >> TenTec at contesting.com
> >>
> http://lists.contesting.com/mailman/listinfo/tentec
> >>
> >>
> >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec at contesting.com
> >
> http://lists.contesting.com/mailman/listinfo/tentec
> >
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
More information about the TenTec
mailing list