The only accurate way to determine key-clicks is by using the method the
ARRL uses in their more recent product reviews. It requires a spectrum
analyzer with 10 Hz RBW, scanning 10 kHz of spectrum using a 30-second sweep
time while running 60 WPM keying. See the chart on page 75 of the February
QST for a chart they ran on the FT-2000.
It was correctly pointed out on another post that key-clicks are not just a
result of rise/fall time, but of leading and trailing edge wave-form shape
as well. The old "ideal" CW shape published for decades in the ARRL
Handbook apparently isn't all that ideal after all!
Ron N6IE
www.N6IE.com
(Formerly N6AHA)
----- Original Message -----
From: "William Q Meeker" <wqmeeker@iastate.edu>
To: <tentec@contesting.com>
Cc: <geraldj@storm.weather.net>
Sent: Monday, January 29, 2007 10:14 PM
Subject: Re: [TenTec] Orion II key click report
>
>>
>
> Jerry:
>
> Thanks for the comments.
>
>>From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
>>Precedence: list
>>Subject: Re: [TenTec] Orion II key click report
>>Date: Mon, 29 Jan 2007 12:26:10 -0600
>>
>>On Sun, 2007-01-28 at 13:15 -0600, William Q Meeker wrote:
>>
>>How much drive power does the PA take?
>
> I get near legal limit with 50 watts output, so never run more that
> when the A99 is on. I usually have it somewhat lower, however, not
> feeling the need to push the limit, even when barefoot.
>
>>The Orion is a bit notorious for
>>setting power only with the ALC while keeping drive up (no adjustment
>>for drive in CW mode) which tends to make a sharp corner when the rising
>>power gets to the power setting, instead of the desired rounded corner.
>
> I followed the related discussion a couple of weeks ago about the
> relationship between the power setting and ALC operation on SSB and
> have been usefully applying what I learned in that discussion to my
> AFSK operations.
>
> I do not know the inner working of the Orion II, but things seem
> different on CW. The ALC light always comes on strong when keying,
> regardless of the setting of the power control (unlike SSB
> operation). Tonight I looked at the keying wave form with the power
> setting varying over the entire range from 1 watt to 100 watts. To my
> eyes, as the power setting changed, I could see no difference in the
> in the ALC light or, after amplitude adjustment, the shape of the
> keying wave form .
>
> Perhaps someone else with better eyes or measuring equipment has
> looked at this carefully for the Orion II?
>
>>Slower rise time doesn't force that top corner rounding. You might try
>>inserting attenuation between the Orion and the PA to allow the Orion to
>>run full tilt so the top corners on the envelope are rounded.
>
>
> I like the idea that my exciter is operating at a comfortably low
> level. I would think that this would have the effect of extending its
> life (in any data that I have ever seen, higher stress leads to
> shorter life---and my wife keep reminding me about this!).
>
>>Scopes are notoriously poor about triggering on modulation envelopes,
>>they'd rather trigger on the individual sinewaves of the carrier.
>>Triggering on the audio or the key closures is more reliable.
>
> I will have to rig something up to do this, when I get some free time.
>
> 73,
>
> Bill
> K0KT
>
>
>>73, Jerry, K0CQ
>>
>>
>
>
> William Q. Meeker
> Department of Statistics
> 304C Snedecor Hall
> Iowa State University
> Ames, Iowa 50011
> Phone: 515-294-5336
> Fax: 515-294-4040
> Home Fax: 515-232-1323
> www.public.iastate.edu/~wqmeeker
>
> _______________________________________________
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> TenTec@contesting.com
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>
>
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