[CQ-Contest] [cwops] WPX CW Signal Quality Concerns

[K9MA]

Rise and fall times don’t tell the whole story. It also depends on the SHAPE of the rise and fall. The cleanest modern radios use their DSP’s to produce nearly optimally shaped rise and fall. (There’s mathematics behind this.)

Before the advent of DSP’s in our radios, I discussed with W8JI the possibility of modifying the FT-1000 to use the CW filter on transmit. Alas, that radio is a nightmare to work on, so I never got around to it.  I think it would have worked, though delay compensation might have been necessary. Maybe next winter. The FT-1000 is otherwise a very good radio.

73,
Scott K9MA 

----------

Scott Ellington

 --- via iPad

> On Jun 6, 2020, at 3:29 PM, Rob K6RB <k6rb58 at gmail.com> wrote:
> 
> You can think of key clicks as sidebands of wave energy caused by rise and fall time modulation of a carrier. The faster the rise and fall, the more sideband energy produced and the wider the bandwidth of signal and its sidebands. If rise and fall are slowed, less sidebands occur up to a point where the keying takes on a mushy sound. The optimal rise and fall is one where keying is not mushy and sidebands are minimized.
> 
> 
>>> On Jun 6, 2020, at 12:03 PM, John McVey - K4AFE via groups.io <mcveyj67=yahoo.com at groups.io> wrote:
>>> 
>> 
>> For those of us who might not understand the issue, could you explain the problem with the key clicks, fast CW rise times, etc., please?
>> 
>> Thanks,
>> 
>> John McVey, K4AFE 
>> 
>> On Jun 6, 2020 13:37, donovanf at starpower.net wrote:
>> That's an excellent step forward Bud.  There's no excuse for intentional
>> key clicks but that's exactly the place where the Japanese manufacturers
>> have intentionally put us in 2020.
>> 
>> The current generation of Japanese transceivers are making key click
>> problems much worse than before.  Our only hope is that contest
>> sponsors improve their rules and enforce them against contesters
>> taking advantage of the fast CW rise time menu options in their radios.
>> 
>> Manufacturers are completely irresponsible with their 4 millisecond
>> default CW rise times and egregiously irresponsible with menus
>> options that allow users to select 1 and 2 millisecond rise times. 
>> 
>> Kenwood and Yaesu provide completely unacceptable 1 and 2
>> millisecond rise time menu options and Icom is almost as bad with 
>> their 2 millisecond menu option.
>> 
>> Why are ARRL and the U.S. distributors not communicating with our
>> Japanese equipment manufacturers about the problems they're causing
>> and enabling?
>> 
>> 73
>> Frank
>> W3LPL
>> 
>> From: "cqwpx director" <cqwpx.director at gmail.com>
>> To: cq-contest at contesting.com
>> Sent: Saturday, June 6, 2020 4:58:15 PM
>> Subject: [CQ-Contest] WPX CW Signal Quality Concerns
>> 
>> I have received two (2) actionable complaints of signal quality issues
>> during WPX CW, which are both under review. 
>> 
>>  
>> 
>> We will investigate additional signal quality concerns.  Please provide the
>> call to be reviewed, along with the date, time and band of the observed
>> signal quality issue.
>> 
>>  
>> 
>> 73,
>> 
>>  
>> 
>> Bud Trench,  AA3B
>> 
>> Director, CQ WPX Contest
>> 
>> web:  <https://cqwpx.com> https://cqwpx.com
>> 
>> email:  <mailto:director at cqwpx.com> director at cqwpx.com
>> 
>>  
>> 
>>  
>> 
>> _______________________________________________
>> CQ-Contest mailing list
>> CQ-Contest at contesting.com
>> http://lists.contesting.com/mailman/listinfo/cq-contest
>> 
>> 
>> 
>> 
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