[1000mp] ARRL testing of Clicks

[Hare,Ed, W1RFI]

This post from Mike Tracy did not make it to the list:

> -----Original Message-----
> From: Tracy, Michael, KC1SX 
> Sent: Monday, July 01, 2002 1:55 PM
> To: 1000mp@mailman.qth.net
> Cc: Hare,Ed, W1RFI
> Subject: RE: [1000mp] ARRL testing of Clicks
 
> Bruce  AA4Z wrote:
 
> > OK, the expanded reports are found in the Members Only 
> > section on the ARRL web site.
 
> The Expanded Report for the Field is not quite ready yet 
> (entirely my fault), but I am working on it right this very 
> minute.  There is a great deal to this report, so it may not 
> be completed until sometime next week.
 
> I will post a follow-up to this list as soon as it is ready.
 
> And now for a comment on this thread (which I've only 
> _partially_ read) - 
 
> Key clicks are *not* generated by short rise and fall times 
> alone - the overall shaping of the wave is very important to 
> the spectral output.  I've done key click testing on rigs 
> with rise times in the 2ms ballpark and found they were quite 
> clean.  What is probably far more important are the "corners" 
> (or lack thereof) near the full amplitude portion of the 
> wave.  If you want to see a good example of a clicky 
> waveform, take a look at the keying on the 817.  I expect 
> that probably goes unnoticed on the air due to the 5W output.
> 
> The original MP was never tested in the ARRL Lab for clicks, 
> as we were unaware of the problem during the review.  
> However, the original ICOM IC-756 did have the problem in 
> early units so there is a point of reference to go by.  At 2 
> kHz spacing, the keying sidebands of the early IC-756 were 
> about 33 dB down in a 300-Hz measurement bandwidth.  
> By comparison, the sidebands of the Field 
> are at 50 dB down at the same spacing.  To me, that doesn't 
> sound like a clicky radio.  Also, it was my impression from 
> posts I read on this list some months ago that this problem 
> only existed in the original MP, and was fixed thereafter.
 
> 73, Michael Tracy, KC1SX, ARRL Lab Test Engineer