[CQ-Contest] Fwd: TX CW “splatter” - context -contests

PHILIP ALLARDICE kt3y at aol.com
Fri Jun 11 12:42:49 EDT 2021

This post is my response to a thread on the Elecraft page, but it applies 
to contesters. I am not a technical expert. Is it possible that “hot switching 
of an amp” causes clicks? Or are there other drivers of CW spatter aside 
from the well documented causes?  I am aware that some modern rigs 
have adjustable waveforms to reduce clicks.

It took restraint to not identify repeat offenders, some of whom are 
often near the top of the MM or SO listings.

Thanks and 73.

Begin forwarded message:

> From: PHILIP ALLARDICE <KT3Y at aol.com>
> Date: June 11, 2021 at 12:22:50 EDT
> To: elecraft at mailman.qth.net
> Subject: TX CW “splatter” - context -contests
> 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

More information about the CQ-Contest mailing list