CQ Worldwide DX Contest, CW
Call: N4TZ/9
Operator(s): N4TZ
Station: N4TZ/9
Class: SOAB LP
QTH: IN
Operating Time (hrs): 37
Summary:
Band QSOs Zones Countries
------------------------------
160: 49 12 25
80: 182 21 64
40: 238 27 87
20: 339 31 99
15: 237 22 79
10: 54 17 32
------------------------------
Total: 1099 130 386 Total Score = 1,566,060
Club: Society of Midwest Contesters
Comments:
The Case of the Empty Six-Pack and the
Curious Association with the Half Loaded Tower
Perry Mason was huddled with his gorgeous secretary,
Della Street, when they heard a knocking sound of
di-dit dit on the door of his private office. Della
exclaimed, "that's Paul Drake's secret knock," as she
leapt to her feet to fling open the door.
Perry said, "Paul, I need your help with another
investigation of the mysterious happenings in the
Black Hole. Weak signals were heard from a long-
silent station, N4TZ/9. Find out why the signals
were so weak and sporadic. The only clues we've
heard involve an empty six-pack and a half-loaded
tower. Lt. Tragg thinks its merely a case of too
many 807s, but I know that Terry drinks nothing
stronger than Diet RC."
******
Paul Drake's Report
N4TZ/9 went QRT in the spring of 2005 following the
January 2005 ice storm that also wiped out N9RV's
antennas. He spent the summer of 2005 working on
building new antennas, and was nearly ready for
installing same when an unexpected addition to
the family caused work on the station to slow
to a crawl. Sporadic progress was made through
the summer of 2006 so that when the final mowing
of hay occurred in October 2006, antennas were
installed. A 5 element 20 meter yagi was installed
at 130 feet with the help of a crane. However,
there were several incidents with the crane and
its operator so that all further installations
were accomplished by two undersized middle-aged
fellows and a hand-operated winch. A full-sized
3 element 40 meter yagi was placed at the 121 foot
level of the tower. Then, on subsequent weekends
they installed a 10-15 meter duo-bander at 99 feet
on a ring rotor, fixed another 10-15 job at 75
feet fixed on Europe and placed a second 5 element
20 with a Cushcraft shorty-forty at 61 feet on
another TIC ring.
Instead of finishing construction of another 10-15
yagi, suspect erected by himself a full-sized
80m four square and a shortened element 160m
four square in his hay field, skipping the Ft.
Wayne hamfest to tune the top loaded 160m elements
and laying 24 radials down for each of the 8 verticals.
Apparently, Terry was relying upon the "cascade of
miracles" approach, because the last thing he did
was install coax and control cables from the house
to the tower and antenna field. He explained that
there was only time to do things one time if he
was going to make the CQWW CQ weekend festivities.
Although many USA contesters for years have been
clamoring for changing the contest to another weekend,
N4TZ did not expect the deadline to move!
On Thursday, the day before the contest, he finally
ran some RF to the antennas. The 80m 4 square had
between one and two watts of power dumped into its
dummy load with 75 watts making it from the house
through 600 feet of flexible coax. The news wasn't
as good with the new 160m antenna - between 25 & 50
percent of the power from the shack was dissipated
in the hybrid's dummy load. No time to make changes.
Check the other antennas. The 20s were fine. Each
of the 40s had good SWR, but the relays in the
Stackmatch at the bottom of the tower was clicking
like a secretary's long fingernails caressing her
keyboard. Terry removed the Stackmatch, patching
the big 40 through to the six-pack. The rotatable
15 showed a very high SWR on the MFJ analyzer, but
the bottom fixed one seemed ok. Made note to check
out the relay box at 80' later. Both the 10m antennas
seemed ok.
The right side of the six-pack had issues. Several
antennas seemed to be selected at once, although
the RF-interlock copied from TopTen Devices prevented
destruction of the Orion connected to it. The
left side seemed to work ok.
Friday morning, an effort was made to finally get
the new K7NV prop pitch to turn. Several days
of effort had found that it turned when the control
box was at the base of the tower, and at the
Polyphasor panel at the end of the house. However,
the Romex through the attic to the shack refused
to conduct enough electrons through the wire to
move the rotor. Three separate 450 foot runs of #12
and #10 wire from the base of the tower through
the second floor shack window provided marginal
excitation to the rotor. A spare 12 volt power supply
was inserted in the common motor return lead from
the M squared controller and the big 20 & 40 yagis
spun like a top.
Since the station hadn't been operated in over 18 months,
the BIOS battery in the shack's computer had died.
No replacements were available for the vintage part,
so TRLog was installed on a Windows 95 computer.
The N4TZ shack relies upon TRLog's reading the
radios' frequencies with a pair of serial
ports and then using a pair of parallel ports to
control the tower mounted six pack. Several hours
were spent finding the secret to making the computer
communicate with the 56k data rate of the Orion; there
was no problem with the OMNI VI on the other side
of the operating table. Just enough daylight was
left for a slow crawl up the tower to check out the
rotating 15m yagi - the MFJ showed extremely high
SWR at the connector near the ring rotor, and the
feedpoint was way too far out on the boom to reach.
All 15 meter operations would have to be done with
an antenna fixed NE.
*****
Operator's statement
A final run-through on the bands from the shack showed
that the 160 meter position had gone bad on both
sides of the six-pack. It was decided to use the
OMNI VI switched for the five high frequency bands
and dedicate the Orion to 160 and the second run
of coax from the shack to the six-pack.
I began the contest gently feeling my way to make
sure I didn't blow anything up. Things seemed to
go smoothly, as I worked most stations heard on
40 & 80 on the first call. 160 was a little
more difficult; I figure that the loaded verticals
were approximately 50% efficient (modeled R was
11 ohms, measured R with radials was about 18 ohms),
and half of that was lost in the hybrid's dummy load.
Combining that with approximately 5 or 6 dB gain
from the 4 square should net me a signal roughly
equal to that from my previous nearly full sized
vertical. Results seemed to bear this out.
Then, Murphy visited again. He first poked his head
in the door when I noticed a buzzing pattern on
the 80 meter monitor scope, later determined to be
the death throws of the six-pack. When daylight
arrived, a trip to the base of the tower showed
that the six-pack was useless. From that point on,
all band changes required the following drill:
1) run down stairs and the length of the house,
out the door, sprint to the tower base, open the
cabinet containing the wiring, unscrew two coaxes
from the shack to the previously selected two antennas
and screw on two different antennas, retrace my steps,
making sure no pets get out the doors. A review of
the log shows I made 14 of these trips, with the
fastest time being 12 minutes.
An autopsy of the six-pack showed that a number of
RF bypass capacitors had developed very low
resistances, effectively selecting multiple antenna
ports. This symptom had previously been noted
several years ago when lightning damaged three
TopTen relay boxes. In that case, replacing all
of the bypass caps with new ceramic discs solved
the problem. The home-brew six pack will receive
the same operation this winter before the next
contest. The final 10-15 meter duo-bander will
be installed in the huge gap on the lower half of
the tower between the lower 20 and the green field
at the base of the tower. Hopefully, that will solve
the Case of the Empty Six-Pack and the Curious
Association with the Half-Loaded Tower.
*****
Summary
I was pleasantly surprised to work as many multipliers
as I did on 15 with the antenna fixed toward Europe.
The Windows 95 computer ran the entire contest without
the need for rebooting, and both radios were perfectly
behaved. After the six-pack emptied out, I decided to
get some serious sleep time each night, which probably
reduced the multipliers on the lower bands.
Posted using 3830 Score Submittal Forms at: http://www.hornucopia.com/3830score/
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