After reading all the comments on this thread, I think that
Skip, K6DWG and Bob, K4TAX have the best theory of what
happened. Careful reading of the SPE 1.3K manual indicates that
the power output of the amp is sampled between the amp and the
internal tuner and that the recommended tune power is 30W.
So the idea that the tuner could have gotten into a state where
it ate the output power is at least credible. I would expect a
KW dissipated in the tuner to have damaged it, but fortunately
that does not seem to have happened.
The manual strongly recommends setting the exciter radio (my K3)
to maximum power output and trusting the ALC to set the correct
drive power. Many here, including me, will disagree. However, as
a result of this recommendation, the manuel doesn't really
address the drive power issue.
Please note that the antenna is driven through coax and not open
wire or ladder line, so theories based on those feed lines don't apply.
Thanks to everyone who replied. This list is a wonderful resource.
73 Bill AE6JV
On 12/27/21 at 2:48 PM, [email protected] (Bill Frantz) wrote:
I didn't have a good night in the K1USN Slow Speed Test. I started
more-or-less on time and tried to answer CQs. None of the stations I tried
could hear me. My SPE 1.3K amp said I was putting out about a kilowatt,
although the antenna tuning on my normally low SWR 40M dipole needed to be
redone. I was receiving many stations, at normal levels.
After a few minutes, I started searching for causes, since
operators calling CQ weren't hearing me and sending CQ again.
Some of these operators had worked other stations, so I knew
their radios were basically working. I tried maybe a half a
dozen stations.
Finally, in desperation, I raised the tune power in my K3 exciter to 15W
and retuned the dipole yet again. Things started working and I managed to
check into the Elecraft 40M CW net via KD5ONS in OR at 0050z. With only 5
minutes in the contest left, I managed QSOs with W6SX and VE5MX. Thanks to
both of them.
My current theory about what was happening is that ice on the antenna was
eating transmit power, although receive seemed normal. Does ice seem a
reasonable explanation? What else could be the cause? I'd love to come up
with a believable answer. Even more so, avoid the situation in the future.
73 Bill AE6JV
-----------------------------------------------------------------------
Bill Frantz | When all else fails: | Periwinkle
(408)348-7900 | Voice and CW. | 150 Rivermead
Rd #235
www.pwpconsult.com | | Peterborough,
NH 03458
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