[TenTec] list opinion(s) on Omni VII and/versus Orion

Mon Dec 10 08:14:29 EST 2018

Great comments Mark!

For many years I was very active on 160M cw and I found that the Orion,
Orion II and RX366 receivers differed somewhat in their ability to handle
s9++ signals, which were encountered regularly in the northeast USA on 160M
cw due to several very powerful stations in this region.  I found the Orion
main rx to be the only one that seemed totally capable of handling the very
strongest signals.  The Orion II seemed to introduce slight audible
distortion on the very strong signals.  I tried several Orion II's and even
went so far as to re-align the Orion II front end per factory specs, which
made no difference.  The RX366 seemed to introduce a strange audible
clicking (hard to describe) when there were many strong signals on the band
in a contest.  Again, I tried multiple RX366's and they all had this
issue.  Finally the stock subreceiver was by far the worst offender and
would produce phantom spurious signals spaced 2-3KHz away from the strong
fundamental signal.  Several users reported this and this was a well known
issue.

I have no theory for why the Orion differed from the Orion II - I assumed
the circuits were identical, but there must be some difference.

All this is from memory, I no longer own the radios.  YMMV

73, Barry N1EU

On Mon, Dec 10, 2018 at 10:43 AM Mark <pa5mw at home.nl> wrote:

> The Orion (565) was never ever tested with the optional INRAD 600Hz
> filter (designed by W4ZV) .
> This 4-pole crystal is the perfect roofing filter with minimal Group
> Delay.  6 or 8-pole filtering, used by the competition, can be good for
> dynamic range specs, but a bad choice on 160m trying to dig out that
> weak signal in the mud.
> Together with the, at the time, exceptional close-by low phase noise its
> receiver still is top-notch.
>
>
> The 2nd receiver is not contest-grade in specs but that is a challenge
> for the real operator using correct ATT +RF-Gain to maximise the use of
> its dynamic range.
> I have never found the theoretical limitation a problem. Not at our
> contest station PI4TUE, nor at home.
> For purists, there is the optional INRAD 45Mhz 4Khz roofing filter. that
> will bring another xx dB's dynamic range.
>
> For those lucky ones there is the TenTec optional RX366 2nd receiver,
> which should have even better specs than the ORION's main RX.
> It is phase locked (can be adjusted on the fly) to the main receiver,
> making it on par with todays competition.
>
>
> The internal sweep panaoramic screenfunction is total useless.
> Today's IC7851/TS890/IC7610 are the best, but still cannot show weak
> signals.
> Any separate SDR, connected or master-slaved(via microham keyer II) is a
> much better solution for the serious contester/DX'er.
>
> Last but certainly not least, making a QSO is about correctlydecoding
> the message from the other station.
> Rob Sherwood mentions this audio reproduction quality.
> This is a much underrated topic at reviewing receivers; can you hear the
> weak signal?
> it is not only about basic distortion at the IF &AF stages.
>
> Filtering in digital domain (like all do today) is hyped for "Brickwall
> filter response for better selectivity".
> People are misguided by these rectangular shaped filtercurves.
> In fact, these curves create massiveGroup delay distortion.
> That is why <200 Hz filterwidth most top-notch transceivers sound hollow.
> You cannot read a weak signal anymore.
>
>
> During my own listening tests I compared typical Icom vs Elecraft vs the
> ORION RX performance and found an 8dB difference between worse(Icom) and
> the best (K2)
> See my measurement results at:
> http://pa5mw.blogspot.com/2009/12/upgrade-current-vhf-station-iv-mds.html
>
> I found that the more round shaped digital filter curves (analog shape)
> performed much better than the sharp edged Icom/K3.
> At the TT ORION one can scout the band at BW=100Hz and not noting it is
> set such small. The reproduced audio is totally free from ringing.
> It is even better than the ORION II which according my measurements,
> seems slightly different tuned; 150Hz BW is the mininmal BW to use
> effectively at weak signal reading on Topband.
>
> For the Icoms there is a powerfull solution; switch to 600Hz and use
> both IF-shifts to dial total BW back to 50 or 100Hz. This makes all the
> difference on especially 50MHz waek signal performance for
> IC756-range/7400/7600
> See also Adam Farson's ICOM pages.
>
> I have not tested any rigs after 2009, but measured the TS590 IF shape
> after I noticed it performs very good. Its filter curve shape(rounded
> edges) show a well found optimum in terms of selectivity vs audio
> reproduction quality.
>
> I am sure the latest generation perform much better at all manufucturers.
>
> Cannot understand why Elecraft did not act here; I have had numerous A/B
> comparisons where the ORION, K2 and even a Drake R-4C can reproduce
> clear audio when the K3 showed ringing zilt.
> Same result can be heard at: https://www.youtube.com/watch?v=FIWSMHkSAXg
>
> Anyone can do this weak signal comparison at home using an old analog
> receiver.
>
>
> YMMMV
>
> 73
> Mark PA5MM
>
>
> On 05/12/2018 17:47, Byron Cordes via TenTec wrote:
> > Nothing wrong with the stock second rx for general rx in the Orion but
> do you really want one in your contest quality Ham Radio ? I think Henry
> was trying to say you can’t cover all the frequency with one radio and not
> to expect a lack of performance somewhere. For the time it was made it was
> first rate and now it’s a fine radio compared to any.
> > Byron AC9PA
> >
> >
> > Sent from my iPad
> >
> >> On Dec 5, 2018, at 1:25 AM, Rick at dj0ip.de wrote:
> >>
> >> Almost all of Rob Sherwood's test reviews are posted on my web site,
> here:
> >> http://www.dj0ip.de/sherwood-forest/sherwood-xcvr-tests/
> >>
> >> I have the OM7 and O2, but I don't have a test of the O1.
> >>
> >> 73,
> >> Rick, DJ0IP
> >> (Nr. Frankfurt, Germany)
> >> May the Sunspots be with us!
> >>
> >> -----Original Message-----
> >> From: TenTec <tentec-bounces at contesting.com> On Behalf Of Rodney
> >> Sent: 05 December 2018 04:55
> >> To: w2iy at verizon.net; Discussion of Ten-Tec Equipment
> >> <tentec at contesting.com>
> >> Subject: Re: [TenTec] list opinion(s) on Omni VII and/versus Orion
> >>
> >> I have had both check Sherwood testing, Orion test is better has 2
> reciever
> >>
> >> -----Original Message----.-
> >> From: Michael Tortorella
> >> Sent: Tuesday, December 04, 2018 10:34 PM
> >> To: 'Discussion of Ten-Tec Equipment'
> >> Subject: [TenTec] list opinion(s) on Omni VII and/versus Orion
> >>
> >> Folks, may we have a brief discussion of the relative merits of the
> Omni VII
> >> and the Orion?  Am thinking of one or the other and would like some
> input.
> >>
> >> Thanks and 73, Mike W2IY
> >>
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