[TenTec] Dirty Transmitters - Flex and Yaesu

[rick@dj0ip.de]

I said it was a fictitious chart.
I just wanted to highlight Yaesu being rock bottom.

And when you say way above the others, I doubt that is correct.
I suspect you are quoting 3rd order IMD "only".
What about all of the other things that can be measured?

I don't have the measured data and am not even smart enough to fully understand it with help from Rob or Jim.
I was just showing an example of what we need to do.

Point us to measured data.
However what we will probably need is to quote data measured by the same lab, which more or less means ARRL.

73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)



-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Greg S via TenTec
Sent: Thursday, December 10, 2015 4:25 PM
To: Discussion of Ten-Tec Equipment
Cc: Greg S
Subject: Re: [TenTec] Dirty Transmitters - Flex and Yaesu

Rick....I see the ANAN with pre-distortion enabled is off your chart (way above the rest) like it was off the ARRL chart in their recent review. ;-) Greg, KC8HXO

Sent from Yahoo Mail on Android 
 
  On Thu, Dec 10, 2015 at 10:08, rick at dj0ip.de<Rick at DJ0IP.de> wrote:   Great idea, Darrell,

I thought about doing that on my web site, but I don't have the technical qualification to do it alone.
I do get about 2000 visitors per day to my web, so a lot of people would see it.

I also thought of the liability of doing such a thing and it kind of scared me.
I got cold feet.

It certainly would have to have a positive name, or else it would be a dangerous liability.
But be honest, if you saw two lists:  Clean Transmitters  &  Dirty Transmitters,  which one would you click first?

The OEMs have deep pockets.
My pockets are shallow with holes in them!

I suppose the list would look something like this:

FICTICIOUS EXAMPLE:

Elecraft K3s
Kenwood TS590S
Flex 6700
Flex 6500
Flex 6300
Ten-Tec Eagle
Ten-Tec Omni 7
Kenwood TS-990S
Ten-Tec Orion
Icom 7800
Icom
Icom
Icom
Yaesu
Yaesu
Yaesu
Yaesu
Yaesu FT-450D  (IMD 29dB worse than a 50 year old 32S3)* Flex 5000

(the order above was picked at random, just as an example)

*This one kind of knocks off Terry's claim that the newer transmitters are basically better.  ;-) This was measured and reported by Rob in several of his presentations - for instance slide nr. 28 of his 2009 BARC presentation.  If you don't have that presentation, you can download it AND the matching audio files here:
www.dj0ip.de/transceivers/sherwood-presentations/barc-2009/
Listen to Rob speak as you manually click thru his slides.

Of course the FT-405D might just be the exception to the rule.
(wishful thinking)

THIS KIND OF LIST WOULD CERTAINLY DRAW ATTENTION TO YAESU - but not the kind of attention they want.
While Yaesu slept, FLEX was hard at work and cleaned up their act.

It would indeed be real interesting to have such a list, but then which criteria would we take.  There are many.

While Joe Ham looks at 3rd order IMD (because that's all he knows), I'm more interested in broadband noise and keying spectrum in CW.

ARMED WITH THIS, I'm sure we would get a favorable response.

It took 30 years to get them to clean up the receivers, but we didn't have the Internet during all that time.
Now, with the Internet, Facebook and Twitter, we could probably see results within 3 or 4 years 

... if everyone would just wake up and shake the boat with us!

Unfortunately, most hams are still asleep at the wheel and many are in denial.

Happy Holidays everyone!

73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)



-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Darrell Bellerive VE7IU
Sent: Thursday, December 10, 2015 2:45 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Dirty Transmitters - Flex and Yaesu

It took a very long time for Rob Sherwood's judgements to take hold and for real change to happen. The fact that some manufacturers are taking steps to improve the cleanliness of transmitters is encouraging. It will take time, but I believe we will see improvement across the board.

I applaud those who, like Rob Sherwood and Jim Brown K9YC, have taken the time to test and document the cleanliness of transmitters. There is great information available to those researching the purchase of a clean transmitter.

The information is quite technical, and there is more than one cause of a dirty transmitter. Not to take away from the great work that has been published, but I have wondered if a "dirty transmitter" or "worst polluter"
list or, with a positive spin, a "cleanest transmitter list" 
would not help promote the idea. A single "score" type of list.

Look at how manufacturers now try to be ranked high on Rob's list of receivers. Perhaps the same for transmitters would help to accelerate the adoption of change. A simple list with a single overall score and then a link to a bit more detailed information. Many hams tend to like the technical side of things and take note of 20 dB less signal 2 kHz from the carrier, but having a single "score" might be a better means to an end.

Developing the score and the criteria for such a list would be more difficult to determine, and certainly in constant dispute, but some form of weighted formula combining issues such as IMD, phase noise, key clicks, etc., to determine the score would be required.

And big numbers tend to be perceived as more valued than small numbers, so make the theoretically cleanest transmitter possible have a score of 1000, and the theoretically dirtiest possible transmitter a score of 0.

It would take a very thick skinned individual to pick criteria, develop a formula for a single score, and publish the list. But I do think such a list would help motivate manufacturers and purchasers to make better choices.

73, Darrell VE7IU


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