[1000mp] Key Clicks -- My MP Experience

[George, W5YR]

Harry, unfortunately it is not as simple as that. One of the key factors in
determining click bandwidth is the manner in which the keying waveform is
accomplished. Specifically, all transitions from off to leading edge onset
to leading ledge completion to full power on, and the trailing edge
counterpart, all tend to contribute added bandwidth unless the transitions
are "smooth." Sharp on/off transitions generate probably as much excessive
bandwidth as does an overly short rise/fall time.

Another unfortunate aspect of keying is that the measures which tend to
minimize artifacts can also contribute to overly "soft" keying which limits
the upper keying speed at which the code can be read in the presence of
noise, QRM, QSB, etc. It is clear that if the rise and fall times are too
great, then there may be no clear break between code elements and everything
"runs together."

It is refreshing to see the amateur community beginning to pay attention to
this problem which has been with us for decades. It is only of late that we
have gotten the receiving equipment and the sophistication in using it to
become aware of the source of all the artifacts and to begin to do something
about them.

73, George W5YR
w5yr@att.net


----- Original Message ----- 
From: "Harry Yingst" <ab2pn@yahoo.com>
To: <1000mp@mailman.qth.net>
Sent: Wednesday, February 04, 2004 12:37 PM
Subject: Re: [1000mp] Key Clicks -- My MP Experience


> The quick way is to look at your signal on an oscilloscope.
>
> If it has a short rise and fall time you most likely click.