[CQ-Contest] [YCCC] Key Clicks in ARRL DX CW

[Jim Brown]

On Mon,2/22/2016 7:06 PM, Jukka Klemola wrote:
> George, others ..
> Please consider the panadapter may show strong signals as wide.

Not GOOD ones, and not if you know how to read the display.  The P3 is 
quite accurate, and compares quite well with my $1,000 ANAN 10E (as long 
as the 10E is not overloaded).

> Most web sdr receivers show strong signals wide.

What's a "web sdr receiver?"

>Please verify the wide signals that they actually are wide.

>In case of strong signals, the actual width may be produced even
>by your noise blanker.

Not width, but certainly clicks. This has been well known for at least 40 years.

>Correct tuning set for the receiver are as important as correct
>settings for transmitter.

Of course. Any front end can overload if overdriven, but it is VERY hard to overload a K3 or K3S. Direct conversion receivers are rather prone to overload of the A/D system, but when that happens the radio "breaks" as long as the overload exists. Digital overload sounds NOTHING like clicks.

I see this post as nothing more than a series of false arguments to deny 
that a signal is wide and or clicky.

The primary causes of clicks are:

1) Excessive rise and fall time of the keying waveform. Even the slowest 
settings of today's JA radios are too fast! The K3 keying waveform has a 
special mathematical shape called a "raised cosine" function. The 
smarter SDR guys are adopting this shaping, and it has made their radios 
cleaner.

2) IMD in an RF stage caused by poor design, DC supply voltage that is 
too low, an overdriven power amp, a power amp that is not tuned right, a 
"no-tune" solid state amp that is not driving a matched load; an 
"auto-recall amp" that is recalling bad tuning.

3) Automatic bias. W8JI has written about this.

4) Using ALC between rig and power amp to set output power. This is 
another major cause of clicks and splatter.

There's a study of ARRL Lab Tests on my website that shows a lot of this 
stuff.

k9yc.com/TXNoise.pdf

73, Jim K9YC