It's usually not that drastic, though. The real meaning is that
transmit power folds back when the K1/2 sees high SWR in order to
protect the PA transistors. Power doesn't necessarily go to zero
unless a really severe SWR was encountered. I made pretty good use of
this in the NAQP contest last evening. Operating 160 meters on my
80/40 trap dipole caused the K2/100 to see just this condition. My
output power dropped quite a bit, but I usually made the QSOs (about
eight as I recall). They were pretty much all locals, but the points
count.
The idea here is that we try to engineer the radios to protect
themselves in the event of a fault (high SWR is considered a fault),
but keep on working. This allows you to finish what you were doing,
then correct the fault as soon as you can and quickly return to full
operation. In my case correcting the fault involves figuring out how
to get a decent 160m antenna on my small city lot. ;-)
Now back to work...
On Jan 22, 2006, at 10:43 AM, Ron D'Eau Claire wrote:
Stephanie, VA3UXB wrote:
I noticed on the Elecraft website, that both the K1 and K2
specifications use the term "SWR-protected" in the description of the
PA transistors.
What does this mean, exactly? If the K1 or K2 is presented with high
SWR, will the radio shut down or shut off or unkey or something?
--------------------------------------
I just had that experience with my K2/100 last night, Stephanie.
I was chatting with a station on 80 meter CW, running 100 watts,
when I
noticed the power output go to zero. I still had sidetone as I
keyed, just
no RF output.
Now, in six years of operation with K2 S/N1289, I've never seen a
burble.
Power was still on, but output was zero. I applied "immediate
action". In
the Army that means kick the [EMAIL PROTECTED] out of your weapon when it jams
in the
middle of battle. On the K2 I was a little less violent: I cycled
the power
off then on again. Keyed the rig and RF output was back and normal.
Hmmmm...
"red flag".... But it keyed FB and I apologized for the break to
the other
guy and continued with the QSO.
A minute or two later it happened again. Cycled power again. Now I'm
wondering if the Astron supply is dying.
A minute or so later it happened again. This time I caught a
glimpse of "HI
REFL..." on the LCD and notice my external SWR meter jump too. So I
signed
and investigated.
I had been swapping cables around and the antenna cable to my
external ATU
was loose and making intermittent connection. When it would break
connection, the SWR went "through the roof" at full power and the
100 watt
amp shut down automatically without damage. Tightening the
connector fixed
the problem.
Ron AC7AC
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