[3830] TBDC K1LT Single Op HP

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                    Stew Perry Topband Challenge - Warmup

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

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

Summary:
Total:  QSOs = 304  Total Score = 874

Club: Mad River Radio Club

Comments:

Since the Stew Perry Topband Distance Challenge, Warmup Edition, is
the first 160 meter contest of the season, there was much work to do
to get the station fully operational.

About 2 weeks ago, one of the ropes that supports the top of the
"tee"
broke.  I temporarily tied it off at ground level so that the antenna
would work.  Tied low, the effective height of the vertical is reduced
somewhat, but the feedline match is better.  I even worked VK9DLX with
it "short".  But psychologically, an inferior antenna is very bad, so
I
endured the sometimes painful process of shooting a line over the
support tree with slingshot, fishing weights, and fishing line.

The first shot misfired, and smashed the 2 oz weight into my wrist -
hence "painful".  The second shot was perfect, but the line broke
trying to pull the rope over the tree.  Then there were a half dozen
misfires.  (I think my technique is declining with age or perhaps with
the age of the wrist rocket).  Eventually, I got a shot over a lower
branch and said the hell with psychology, this will work fine.  The
poison ivy infection usually goes away in less than a week.

The beginning of every season entails visiting all of the short
verticals to clean out the ants and make sure all have proper SWR
curves.  Typically, the ants breach the screen over the weep hole and
move in, or a capacitor fails, or a top-hat / guy line breaks, or
something else completely befuddles me.

On the newer array, I switched from plastic screen to aluminum screen,
which has slightly bigger holes, and some ants can get in without
chewing a hole.  By accident though I discovered that if I use a clear
lexan cover over the junction box that houses the matching network
instead of the proper opaque cover, the ants don't move in.
Alternately, sprinkling some ginger in the box dissuades the ants from
moving in.  However, the ginger powder eventually turns into muck.

My newer PVC based verticals seems to hold up better than the 2x4
version, so as the 2x4s break, I've been rebuilding with 23 feet of
1-1/2 inch PVC conduit, and an end cap.  I drill 4 holes in the end
cap for the top-hat wires, and put 1/4 inch clear PVC tubing over the
wires as a strain relief, and make the electrical joint inside the
cap.  The lighter PVC, the strain relief, and the immobilized
electrical joints seem to last longer, although the oldest vertical is
only 2 years old so far.

One vertical had a somewhat high impedance compared to the others, so
I built a new ground radial system which when added to the existing
radials cured that problem.  The old radials on the original 2x4 BS-EF
array used random lengths of old telephone twisted pair from a
multi-pair cable.  These radials were meant to be throw-aways, but the
original prototype worked so well that the prototype was placed in
production without any upgrade.  (Where have I seen this pattern
before?)  The new radial system is 16 23-foot #13 enameled wires
silver soldered to a #6 copper wire bent into a 6-inch diameter
circle.  The #13 wire is surplus transformer winding wire.

I tried the same trick on another vertical but the extra radials had
no effect on the feed impedance.  That vertical turned out to have a
bad solder joint that removed one of the tuning capacitors.
Strangely, the effect was higher impedance at the point of lowest
reactance, but not much change to the frequency of lowest reactance.

Last spring the 160 position of the Alpha 8410 stopped working because
I fried the band switch.  The 8410 uses a 20 degree per position band
switch that has 9 positions.  Thus each band has a unique inductance
value but it is very easy to miss the detent such that the switch is
not fully engaged with a particular position.  Then when one sets the
tuning controls using presets and applies full power, a serious arc
develops across the band switch and rapidly melts something.  In this
particular accident, the vaporized contact switches in extra
capacitance on 160 meters, so that band no longer works.

I ordered a replacement wafer from RF Concepts.  It looks like I can
pull the shaft out of the band switch, spring open the circlip and
replace rotating portion of the wafer to effect a complete repair.
However, it appears that getting the shaft out of the band switch
requires the front panel to be disassembled, so I haven't tried to do
this yet.  Why don't I just ship the amp back to RF Concepts??  I'm
cheap!  I like fixing my own stuff.  I used K8ND's ETO 91B for this
test, for the last time, since Jeff wants his amplifier back.  Thanks,
Jeff!

After talking to NO3M about his audio routing scheme, I decided to try
something similar here.  The simplest scheme connects both receivers
(the K3 and it's diversity sub-receiver and the phased-array receiving
system) in parallel.  Then I can hear in 4 directions simultaneously.
When the caller is very weak, I have to determine which receiver is
hearing him, and turn off the audio from the other receiver.  But much
of the time, I just hear one signal in one ear.

In practice, this audio routing seems to work.  Most callers are not
that weak, so normally nothings needs done.  When the caller is
sufficiently strong and both the phased array receiver and the K3 on
the Beverages hears him, then I have to turn off one audio because the
SDR receiver has a 20 millisecond lag compared to the analog receiver
and the "long delayed echo" interferes with CW comprehension.
Unfortunately, in this simple lash-up, turning off the phased array
audio is just a toggle throw, but then I miss 20 milliseconds of CW
which corrupts one letter.  Turning off the K3 audio requires getting
my fingers onto the concentric audio knobs and rotating through more
than 180 degrees which misses many letters because my fingers are
slow.  So I requested a lot of callsign fills, especially from strong
stations.  I'll build some sort of decent audio mixer with proper
switching for the next contest.

Oh, and I operated the contest.  Conditions were quiet but activity
seemed low.  Worked OK2WM early, and then didn't hear any Europe until
a very brief run around 0540Z.  Also, I seemed to hear Europe better
on the Beverage than on the phased array.  I don't know if that means
my array is functioning poorly or if there is some special propagation
that somehow favored the 30-degree Beverage over the phased array.

Worked KH6ZM as my second best DX but hearing him was quite a
challenge.  VK9DLX was very copiable just before sunrise, but he was
giving out DXpedition 5NNs, not contest grids.  I didn't hear any
other western DX.  The 4-way audio system payed off when I finally
worked HC2AO, who has been regularly calling me for the past year
without success.

Wound up with 305 QSOs compared to 350 last year (including dupes).
Also, I noted that the activity started later, started much more
thinly, but seemed to be more intense near the end of the night.
Maybe the NYQP is more interesting to many people.

Surprise DX since there aren't any multipliers: NU4Y/VP5, XE3ARV, and
HC2AO for never before received grid squares.  For some reason,
copying a new 4 character locator is just as much fun as working a new
country, even if I've worked that country before.

Equipment: K3, P3, ETO 91B (thanks, Jeff!); 2 x 4 BS-EF phased array,
2 x 3 BS-EF phased array, 65 foot "tee" with an ever declining
number
of effective radials; too much software.


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