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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