Key Clicks? Huh?
----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, January 29, 2007 1:26 PM
Subject: Re: [TenTec] Orion II key click report
On Sun, 2007-01-28 at 13:15 -0600, William Q Meeker wrote:
I have been playing in the CQ WW 160 meter contest over the weekend.
Last night another ham, about 20 miles away spotted me on the cluster
with the comment "with clicks." I am using my Orion II (version
2.037j) and was running close to the legal power limit (Alpha 99)
with a separate receiving antenna so that I do not have to exercise
the A99's relays.
After that report came through I immediately checked the setting in
the Orion II and it was at the recommended default of 5 ms, and
because I have never had any other reports like this in the 5 months
that I have had the Orion II, and I know that strong stations can
overload a receiver to cause clicks, I just continued on.
This morning, after the band closed, I hooked up my monitor scope to
have a look. The wave form looks good, but I have not figured out
some kind of standard so that I can measure the exact rise/fall time.
In looking at the archives of this list I saw an old posting that had
measured the actual rise/fall times against the settings and found
that the actual times were less. To be safe, for now I changed the
Orion II to 7 ms.
A few questions:
1. Has anyone measured the rise/fall times in this version of the
Orion 2? How accurate is the rise/fall time setting of the Orion II?
And of course, as a statistician, I wonder if this is consistent over
different units. If several people have done the measurements, we
could sort this out.
2. If my rise/fall times are set a 5 ms, and the wave form shape has
the right shape on my scope, could I still be creating objectionable
clicks?
3. What other things should I do to check for the clicks?
4. In the Orion II manual (October 2006 version) on page 31 is says
that "For external keying the rise fall times available are 3ms to
5ms regardless of the keyer speed." I can adjust between 3 and 10, so
I suppose that this is a typo?
Bill
K0KT
How much drive power does the PA take? 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.
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.
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.
73, Jerry, K0CQ
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