Re: [Elecraft] TX CW “splatter” - context -contests

2021-06-13 Thread Jim Brown

On 6/11/2021 9:22 AM, PHILIP ALLARDICE via Elecraft wrote:

I am using the term CW splatter to cover clicks, phase noise, IMD
  and  other hallmarks of a wide signal.


Clicks and what we have long called splatter ARE exactly the same 
mechanism -- intermod distortion of an amplitude modulated signal. In 
the case of CW, its 100% amplitude modulation of a carrier by a 
rectangular keying waveform. Phase noise is an entirely different 
mechanism.


73, Jim K9YC
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[Elecraft] TX CW “splatter” - context -contests

2021-06-11 Thread PHILIP ALLARDICE via Elecraft
I am using the term CW splatter to cover clicks, phase noise, IMD 
 and  other hallmarks of a wide signal.
>> 
>> To me, the graphs presented by K9YC are compelling.  It is clear that a 
>> number of modern radios are significantly “dirtier” than others, while  a 
>> TS590,  that currently costs under $1500 at DXE, looks quite clean. The 
>> charts display TX spectrum images from mid range transceivers to 
>> premium rigs (15 rigs total) such as the K3, Flex and others.  Take a 
>> look at K9YC.com/TXnoise.pdf.
>> 
>> A dirty TX rig has much less impact on casual operating, or even most
>> Dxing, as the band isn’t usually crowded.  It is another story in a contest 
>> as many offenders run HP with huge antennas. They are LOUD. I have had 
>> to move many times when a loud, splattering CW signal parks a few 
>> KHZ away.
>> 
>> The cost of a clean TX is insignificant compared to such station’s antenna, 
>> feedline and tower investment- plus all the other peripherals such a BPFs.
>> 
>> Anyone who operates contests has heard such signals many times.  
>> It begs credulity that owners who are serious competitors aren’t aware 
>> of the issue. But it appears that little is done as most hams (including the 
>> log checkers) are reluctant to press.   Rather than ignore the issue, radio
>> manufacturers need to lose sales due to poor TX performance by hams 
>> voting with their dollars.  I am glad the ARRL now takes a more proactive 
>> role in evaluating TX performance. 
>> 
>> I understand the argument that we need to encourage activity, especially 
>> from modest stations. I could not agree more, but in contests it is the loud
>> stations with dirty signals -often using big antennas- that affect other 
>> competitors adversely, not just those nearby. 
>> 
>> It is time to place as much emphasis on a clean TX as on impressive 
>> receiver specs. Some manufacturers, including Elecraft, already have.
>> 
>> The CW splatter problem is noticeable  in EU and NA, sometimes emanating 
>> from huge MM stations. I imagine that it occurs worldwide, but the Asians 
>> are 
>> not generally that loud so their splatter is buried in the noise.
>> 
>> 73,
>> Phil KT3Y- KP2M
>> 
>> 
>> 

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