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

Mark pa5mw at home.nl
Mon Dec 10 05:26:31 EST 2018

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 
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: 

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 
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 


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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