[CQ-Contest] Key Clicks.... Continuing Problem

Fri Nov 13 21:30:38 EST 2020

I must admit some surprise that a task like this would fall into the domain of a Director of the League.  Are there not staff to handled such details?  This seems like a perfect tasking for the underutilized Contest Advisory Committee.

This is also a much more difficult topic to write rules around than it might seem.  The CQ WW added rules about signal quality a few years ago. The following falls under section XII.A Unsportsmanlike Conduct. "Signals with excessive bandwidth (e.g., splatter, clicks) or harmonics on other bands."

Several of the CQ WW Contest Committee members have spent time trying to come up with a more formal definition of wide signals that could be used with audio recordings to make a solid case.  I.e., something more than "knowing a bad signal when we see it."  It has been a challenge.  Jukka OH6LI did a write up on SSB signal quality at https://www.cqww.com/ssbsignalquality.htm

It is probably best not to tie to specific rules or technologies.  Bandwidth seems to be the best metric for determining signal quality.  A signal is either within expected norms for the given mode or not.  The challenge is how to measure that after the contest.

73,

Randy K5ZD

-----Original Message-----
From: CQ-Contest <cq-contest-bounces+k5zd=outlook.com at contesting.com> On Behalf Of Michael Ritz
Sent: Friday, November 13, 2020 5:50 PM
To: cq-contest at contesting.com
Subject: Re: [CQ-Contest] Key Clicks.... Continuing Problem

Not that it means much, but I am in the process of updating the ARRL General Contest rules to include "clean signal" requirements, including key clicks and splatter. Right now there is only a general "entrants are bound by regulations of their national licensing authority" in the ARRL rules. That implies FCC Part 97.307 for US entrants, but what about everybody else in the world?  

What I'm proposing to add "Each participant in an ARRL sponsored contest shall take precautions to ensure that all signals emitted are free from excessive bandwidth, splatter, key clicks, or other spurious emissions". 

As far as adjudication, I'm adding under "Disqualification and Penalties": "Unsportsmanlike conduct will not be tolerated in ARRL contests. The ARRL reserves the right to take disciplinary action, up to and including disqualification, for entrants that violate this rule. This includes the emission of signals that do not meet applicable standards as specified...."

Keep in mind that we (the ARRL) now have a pretty sophisticated Volunteer Monitor program in place, and they are looking for not only band-edge violators, but signal quality violations as well. Of course, still only for US entrants. 

73;
Mike
W7VO

> On 11/12/2020 1:50 PM Jim Brown <k9yc at audiosystemsgroup.com> wrote:
> 
>  
> Great post, Jim. Thanks!
> 
> Based on what I learned doing that study several years ago of ARRL Lab 
> data, I completely agree. There are other things we can do as well.
> After I gave a preliminary version of that study to someone who I 
> strongly suspected would pass it along to Yaesu, whose radios were the 
> worst offenders, a firmware upgrade for that series of radios was 
> released that improved keying to the extent that it looked more like 
> the second worst offender (of that generation), ICOM. :)  If you have 
> one of those rigs, by all means install the upgrade. I did before and 
> after measurements of keying bandwidth on a neighbor's FTDX500. They are here.
> 
> http://k9yc.com/P3_Spectrum_Measurements.pdf
> 
> The study of ARRL Lab data is here.
> 
>   http://k9yc.com/TXNoise.pdf
> 
> Yes, the slowest possible rise time should be used when it can be 
> adjusted. The reason no adjustment is needed (or possible) with 
> Elecraft rigs (beginning with the K3) is that the keying waveform is 
> carefully shaped for maximum clarity and minimum clicks. Flex adopted 
> this a year or so after ARRL Labs first tested the 6500 series. I 
> don't know if they've tested those rigs for keying bandwidth after that upgrade.
> 
> Another major generator of clicks (and splatter) is the use of ALC 
> between the transceiver and the power amp to control power. In 
> general, that form of ALC should ONLY be used to protect the amp from 
> faults in the antenna system, including the operator transmitting into 
> the wrong antenna. :)
> 
> I haven't studied the current generation of Yaesu rigs on CW, but the 
> lower cost models generate terrible splatter -- typically 2 kHz or 
> more on both sides of their intended bandwidth, only 20 dB down. That 
> is, 2 kHz on the suppressed side of the carrier, and 4-5 kHz on the 
> other side of  suppressed carrier. I discovered this when helping a 
> neighbor figure out why his new Yaesu was splattering, also by 
> observing it on other signals, alerting the splattering station, who 
> told me what rig he was using.
> 
> Obviously, if the transceiver is generating the splatter (or the 
> clicks), the power amp will amplify it (and maybe add more of its own).
> Think about it -- if someone with one of these rigs is 30dB over S9 in 
> your receiver, his sidebands will be 10 dB over S9, not great if 
> you're trying to work someone on an adjacent frequency.
> 
> Yes, there were some very clicky signals this weekend. Thankfully 
> fewer, as Elecraft and Flex rigs continue to proliferate.
> 
> 73, Jim K9YC
> 
> On 11/12/2020 9:23 AM, Jim McCook wrote:
> > Anyone who has been operating in CW contests is aware of the rampant 
> > key click problem we all must deal with.
> > 
> > If you are using a JA made radio, please check the CW rise time to 
> > be sure it's set to 8ms (unless 6ms is maximum... which needs to be 
> > changed).  Also check to be sure you're not hot switching your 
> > amplifier.  Key clicks in contests have become a serious problem and 
> > it's long overdue for resolution.  If you use an older JA radio 
> > without that adjustment, there may be a key click mod that will 
> > eliminate those clicks.
> > 
> > There is a reported case of a radio set for 8ms being sent to the 
> > manufacturer for repair and was returned with a 4ms setting. Please 
> > check after such repair returns.
> > 
> > Elecraft and Flex users need not be concerned unless something is 
> > wrong with the radio.
> > 
> > 73, Jim
> > W6YA
> > _______________________________________________
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> > CQ-Contest at contesting.com
> > http://lists.contesting.com/mailman/listinfo/cq-contest
> 
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