[CQ-Contest] Rig Comparisons for Transmitter Noise

[David Siddall]

"Mark IV" should be "Mark V", of course.

On Wed, Sep 10, 2014 at 9:51 AM, David Siddall <hhamwv at gmail.com> wrote:

> Jim,
>
> With regard to transmitted trash and technology, at the ARRL Centennial
> convention this summer NR0V received the ARRL Technical Innovation Award
> for developing his "Pure Signal" software.  It runs on digital rigs such as
> the Anan and any other with open source software, and with last week's
> announcements from FlexRadio providing an open path into their 6000 series,
> undoubtedly some form of adaptive predistortion for those radios will be
> available soon.  Others will follow.  One nice thing is that continual
> improvements will be implementable rapidly as new amateur transmitters
> increasingly enter the digital domain.
>
> Maybe the larger issue is the disincentive to run clean signals.  It is a
> typical "tragedy of the commons" situation.  Contesters running NR0V's Pure
> Signal would enable OTHERS to hear the weak ones, but would be
> disadvantaged by competitors running their older technology radios (such as
> the FT1000MP Mark IV as you point out) by trashing the frequency used by
> the operator with the "pure signal".  In this regard, the recent rules
> change in the CQ contests requiring at least halfway decent transmit
> signals is a small step, and more importantly a push in the right direction.
>
> As an aside, in this year's ARRL phone DX contest I had to substitute out
> my Flex 6500 at the beginning of the contest (due purely to operator error
> I later found) and I only had an FT1000MP Mark IV available.  Fortunately
> it was SSB, not CW, but even then I ran it in class A hoping it would be a
> little cleaner.
>
> 73,  Dave K3ZJ
>
>
>
> On Sun, Sep 7, 2014 at 5:28 PM, David Siddall <hhamwv at gmail.com> wrote:
>
>> Jim,
>>
>> Good stuff, thanks!
>>
>> I also recommend K3NA's article on adjusting SSB audio chain.  While
>> specific to Orion, the principles are adaptable any any rig.
>>
>> http://www.k3na.org/articles/Transmit%20audio%20adjustment.pdf
>>
>> 73, Dave K3ZJ
>>
>> On Sun, Sep 7, 2014 at 1:13 PM, Jim Brown <k9yc at audiosystemsgroup.com>
>> wrote:
>>
>>> Over the last decade or so, Rob Sherwood's extensive work on receiver
>>> performance has done much to improve the receivers in modern rigs, but
>>> transmitters have been sadly neglected.
>>>
>>> A month or so ago I began work on a project to compare ARRL test data
>>> for selected rigs, focusing on the trash they generate. I shared an early
>>> version of that work on the Elecraft reflector, and it seems to have found
>>> it's way to Yaesu, who has just put new firmware on their website to
>>> improve the CW waveform.
>>>
>>> I've done a lot of work on the piece since then, and it's near its final
>>> form. If you're thinking about buying a new rig, it should give lots of
>>> food for thought.
>>>
>>> http://k9yc.com/TXNoise.pdf
>>>
>>> Also, if you haven't already done so, see the slides for K6XX's
>>> excellent presentation on Signal Cleanliness, which, among other things,
>>> shows how we can set up and operate our existing rigs to produce a cleaner
>>> signal.
>>>
>>> k9yc.com/K6XXAmpTalk.pdf
>>>
>>> 73, Jim K9YC
>>> _______________________________________________
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>>>
>>
>>
>