Hi Mike (Bates) .... we have so many Mikes!
Your point on the reciprocal mixing is well taken but at least for now, I
feel you are over-rating the value of doing that. In the interest of
advancing technology, yes but how much actual on-the-air benefit would one
get - especially if one is not a CW contest operator?
As Rob Sherwood and Adam Farson (and others) have often said, the biggest
problem facing us on the bands now is the dirty transmitters. Improving
reciprocal mixing won't help there.
As long as I can remember (abt 40 years), people have been asking the same
question, "how much performance do we really need?"
The answer has migrated upwards as the bands became fuller and fuller and
more and more people were able to afford linear amplifiers (and some
not-so-linear amplifiers).
At one time Rob Sherwood stated that BDR3 was the single most important
figure for measuring performance and we followed that path for many years.
When the FLEX 3000 and 5000 came out, they had outstanding BDR3 numbers but
their on the air performance under certain circumstances did not pan out as
one would expect based on that number.
The definition of performance now is far more complex than BDR3 and I
contend that it has almost become a meaningless number... just as
sensitivity has. Now days, by default all radios must have good sensitivity
and DR3 as a given. Other things will determine the ultimate performance,
some hardware based (i.e. synthesizer filtering) and others software based
(i.e. dithering).
Mike, I assure you I agree with your idea of where the future should go, but
I would add that "cost of Xtal filters" is a bigger reason to do that than
improving reciprocal mixing. The good news is, we get both if we choose the
right route.
73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Mike Bates
Sent: Tuesday, February 21, 2017 1:25 AM
To: tentec@contesting.com
Subject: [TenTec] EAGLE II Features - more thoughts
Hi Rick,
I first applaud Mike Dishop for his efforts, and really hope that Ten Tec
and Alpha succeed. I agree with you, on your points. One thing that has
changed in the 7 or so years since the Eagle was released is the improved
reciprocal mixing performance of the new radios. While the Eagle is good, it
is no longer in the tier it was in when it came out.
Improving the reciprocal mixing performance would go a long way toward
raising the close in dynamic performance. This is one area where the direct
sampling SDR's have an advantage, for a low cost. Making a rig similar to
the feature set of the Omni VII, or possibly some fewer features, using the
basic Eagle receiver.
Items that are Ten Tec strengths:
*Receiver/Transmitter Audio Performance
*Limited use of deep menu's/ease of use
*Good practical S/N ratio, when using the RF gain properly, the signals just
jump out of the noise. (better than most)
*Filters select-able independent of mode
* Passband tuning that shifts the whole passband in any mode
Items that would set the rig apart form others:
*Packaging - use more commercial type of packaging, possible rack mount
kit. (Commercial Grade)
* Design to be durable, high mean time between failure. (Commercial Grade)
*Design front end for new 630 and 2200 Meter Band, as well as good
performance on the AM broadcast band.
Other desirable items:
* Design for 2 roofing filters per mode SSB/CW and a wide one 15KHz (AM &
FM), and one AM at 6KHz (places for 6 roofing filters if the user wants.
Ship the rig with one 2.4 KHz SSB filter to keep costs down).
*Improved Phase noise/reciprocal mixing performance, minimum 100dB@2KHz
spacing (Reciprocal mixing).
* Provision to connect an SDR to the 9MHz IF, as a pan-adapter. Provide
buffering, to make it plug and play. (BNC connector).
* Provision to add a second receiver, and have a receiver Antenna Port
(SO-239 or BNC). No RCA jack!
*Larger Display than the current Eagle. Meter that is easier to read and
calibrated in both S units and dBm.
I agree with others that there is still a niche market. The 7300 has really
caught on, but a good basic rig with high performance will still sell. I
would argue the main competitor for something like this is Elecraft, but
there are differences on ergonomics and some performance parameters. I think
keeping things simple while having really good performance (RF and Audio)
throughout the covered frequency range is important. The existing Eagle
modified and brought up to date would be a really good starting point.
I realize that some of these items such as the commercial type of packing
and failure performance may cost more, but will set the rigs apart from the
competition. They could be even offered as two separate models, or may have
a limited market, but I thought I would put it out there.
I also think that it would be OK to try a run of Eagles, and Argo VI's, as
well as Antenna Tuners and other accessories mentioned to help with new
development, but I feel that revisions should be started, and we should
hopefully see something in the future.
Wishing success going forward to Mike and his crew.
73,
Mike Bates KA0KLQ
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