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
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