[3830] TBDC K1LT Single Op HP

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Sun Oct 23 09:09:30 PDT 2011

                    Stew Perry Topband Challenge - Warmup

Call: K1LT
Operator(s): K1LT
Station: K1LT

Class: Single Op HP
QTH: EM89ps Ohio
Operating Time (hrs): 11

Total:  QSOs = 334  Total Score = 1,390

Club: Mad River Radio Club


First, an antenna maintenance story.  While futzing around the shack
making everything tidy before the contest, I decided that I could
tighten one of the 2 ropes that supports the "Tee" top of the
transmitting antenna.  I expected that raising the wire slightly would
restore the proper resonant frequency and SWR, as the lowest SWR
frequency had drifted a little high in the band.

So, out into the field on a nice day to tug on a rope.  When I get to
the rope, I noticed that the rope looked a bit ragged 50 feet up in
the tree. Fortunately, I brought replacement rope and sling-shot and
fishing line just in case.  Yup, I was afraid of that - I untie the
rope at the bottom but it doesn't slide through the tree.  OK, just
shoot a new line over the tree and put up the new rope since I knew
the old rope was due for replacement.

Drat!  The first shot misfires.  Reload.  The second shot tangles all
the fishing line.  I've learned over the years its not usually worth
the trouble to untangle and reuse fishing line.  Double drat!  Not
enough line on roll for another shot.  Try anyway, launch sinker into

Back to the house to get another roll of fishing line.  Uh oh!  Can't
find any.  Panic, then finally find a roll.  (Mental note - buy
lifetime supply of 20 pound fishing line and 3/4 ounce sinkers).  Back
to the field.  Well, instead of shooting a new line over the tree,
I'll shoot a line over the old rope and pull it down from the antenna
side and use it to pull the new rope through the tree.  Dang!  The
rope broke in the tree.  2 hours until on-the-air time, and now the
transmit antenna is broken.  Curse myself for not doing maintenance in
a timely fashion.  Shoot a line over the tree and succeeded in pulling
up the new rope.  Finish up in the field and go back to the house.

SWR is exactly the same as before.  Well, at least the "Tee" top has
new ropes (changed the other side right after it broke earlier in the
summer).  Not being one to learn a painful lesson, go back out in the
field and tighten the rope.  

Next, another software radio while contesting story.

Last year I modified the version of SDR-Shell that I use with the beam
steering phased array antenna / receiver so that I could poke numeric
keypad keys to turn the beam by setting up a TCP connection from
SDR_Shell to my Phasor program.  This arrangement avoids having to
constantly use the mouse.  Then I would operate a contest and discover
half way through the contest I could not switch the phased array to
directions west.  So, this year I tried to fix the problem that I
assumed was caused by RF getting into the USB controller that drives
the relays by adding a bunch of common mode chokes to all the cables
going to the SDR receivers.  I also added an LED so I could monitor
the state of the relay power.

When 2130Z rolled around, I wondered why there were no signals on the
waterfall.  Maybe everyone was still on 10 meters.  I let out a CQ
anyway and got a bunch of answers, but noticed that I still didn't see
any signals on the waterfall (or hear them through the phased array
audio channel).  Light bulb!  I had plugged the audio cables in to the
receiver array backwards, which flips the spectrum upside-down with
respect to the local oscillator.  In other words, the SDR receivers
were listening to the SSB half of the band.  I quickly swapped audio
cables and figured I was ready to really contest.

A little while later I noticed that I still couldn't switch to the
west.  The LED would not light up when I pressed the "west" buttons on
the keypad.  But the LED would light if I used the mouse to click on
the compass rose on the Phasor program.  That meant he problem was not
RF induced, but a stupid programmer trick.  So, between contacts on
the K3 receiver and the Beverages, I tracked down the missing "set
relays" statement in the Phasor program and recompiled.  Bingo!  Full
control again.  This fix demonstrates the "software" benefit of
Software Defined Radio.  Of course, its better not to make the mistake
in the first place.

The rest of the contest was reasonably uneventful.  Conditions were
much better than last year when I worked only 3 Europeans.  So maybe
sunspots aren't as bad as I thought.  At one point, DL5KUT started
CQing on my run frequency.  He obviously couldn't hear me, but I could
hear him and the European stations he was running.  However, the
static to the west and southwest was very cruel.  Also the QSB during
the first half of the night was very obnoxious.  My apologies to those
of you who vanished before completing an exchange.

Didn't hear any VK, ZL, or JA.  T32C was strong while TX7M was weak.
(TX7M wasn't in the contest but I worked him for the new band entity.)
I think the strong static discouraged a lot of stations.

Equipment: K3, beam steering phased array antenna / computer /
receiver thingy, ETO 91B (as always, thanks K8ND), 12 Beverages, 65
foot "Tee" over 80 125 foot radials on the ground (or actually mud at
the moment), Writelog, and custom software kludges to tie it all

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