[3830] TBDC W2GD Multi-Op HP

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                    Stew Perry Topband Challenge

Call: W2GD
Operator(s): K2SG, K2TW, N2HM, N2OO, W2GD, W2NO
Station: W2GD

Class: Multi-Op HP
QTH: West Creek, NJ
Operating Time (hrs): 14

Summary:
Total:  QSOs = 574  Total Score = 3,760

Club: Frankford Radio Club

Comments:

A Winter Field Day at the New Jersey Shore - The Adventure: Part 2
(A long story)

Planning and Station Preparations

At the conclusion of the ARRL 160 contest 3 weeks ago, we left the site of our
FD-style operation on the Jersey shore with a long list of "issues" that needed
some serious attention and workable solutions.  Most important of  the these
problems, both transmit antennas were in a "wounded" state after sustained
punishment from two Nor'easters the previous month - making repairs and
adjustments would be our first priority.  Our other big concern was a very
serious "RF in the shack" condition we’d endured during the ARRL weekend that
were not been a factor the past two years.  High RF levels had caused havoc with
operation of computers, rigs and phone lines.  We decided Stew Perry weekend
would be an ideal opportunity to make needed antenna and station repairs and
then test everything as part of preparations for the CQ160M CW contest in
January..  And once it was decided to go High Power, the level of enthusiasm
among several team members markedly improved....painful memories of last year’s
Low Power effort using mediocre antennas still lingered.

Its obvious that running high power in the SPTC has significant scoring
disadvantages, and most years running HP is an almost certain ticket to "also
ran" status in the final results.  SPTC rules give LP and QRP stations a nearly
insurmountable scoring advantage over HP entrants.  Knowing this, an operating
strategy with an almost singular focus on working Europeans was devised...it was
our only hope of generating a score large enough to be competitive with the
lower power classes.  

In prior postings I've mentioned our station by the sea is located at the end of
Murphy Drive.....honest!  This weekend it sure felt like Mr. Murphy was away
vacationing in South America, Brazil perhaps..  Sunrise on Saturday morning
revealed a cloudless sky, not much wind, and rising temperatures - a simply
fabulous winter's day for antenna work.  Arriving at the site just after 9 a.m.
(a two hour drive for many of us), we made quick work of hooking up the NE,
South and West beverages that we'd used for the ARRL 160, and then brought out
more feed line and 9:1 transformers to bring the SW, NW and East beverages
on-line for SPTC weekend.  Later in the evening we'd discover the two element NE
phased beverage array was in "cone of silence" condition - W's simply
disappeared when in use.

Next we turned to repairing the Inverted L.  Six weeks earlier the feed point
impedance was 13 ohms.  On ARRL 160 weekend it measured 33 ohms.  Something had
definitely changed, but bad weather and lack of time prior to the ARRL prevented
any real investigation of why at the time.   Walking the 4 elevated radials, we
quickly found the problem....one of the radials was lying against an abandoned
long wire rx antenna left on the site by previous owners, the radial was
effectively detuned.  Moving the element 3 feet away brought the impedance
reading back within the expected range.  After installing a 4:1 unun and some
minor adjustment to the length of the horizontal leg brought the entire system
into a reasonably tuned state.  TX antenna #1 was ready for final adjustments. 
We’d later add a newly wound solenoid RF choke constructed based upon a design
posted by W1JR on the Top Band Reflector last week..

Four of us then focused our attention on the main task of the day, repairing and
tuning the multi-element vertical array hung off the 300 foot tower surrounded
by saltwater marshland – boots required!  Before the ARRL, one of the recent
Nor'easters had caused the failure of one of two one-half inch nylon pull ropes
strung through stainless steel pulleys at 200 foot level.  This rope held up 
the SW driven element of the array.  When the rope let go, one end wrapped
itself around a guy wire insulator about 150 feet up, and 40 feet away from the
tower, with the antenna element still attached.  The challenge would be to
somehow pull the whole mess cleanly up and off the guy wire while perched above
at the guy attachment point at 180 feetl.  Only two members of our team climb
towers this tall, and one had just returned from the chiropractor that morning,
so your's truely was elected to make repairs..  This was definitely another case
where Murphy was away on vacation, because pulling the rope in toward the tower
came off without a hitch ....the inherent stiffness of nylon rope exposed to a
salt water environment for 2 years had fortunately prevented the fibers from
fraying into a fatal entanglement on the guy insulator clamps.  I was so
thankful...the alternative repair scenario which would have required dropping
the guy wire to reach the tangled mess was not feasible with our time
constraints. After cutting off 40 feet of damaged rope, it was quick trip up to
200 feet to restring the rope through the pulley and then finally back down to
terra firma.  Total time on the tower was just an hour – but it seemed longer. 
The great weather also provided an opportunity to take some new pictures from
that perch high above the salt marsh and adjacent Barnegat Bay.  The view of the
salt water ground plane in the near field of this antenna system is truly
impressive.   We'll post the pix somewhere for viewing soon.

Our primary TX antenna consists of three elements.  In the center a one
wavelength delta loop is hung nearly flush with the tower and acts as the array
reflector. 1/2 wavelength sloping dipoles are pulled away toward the NE and SW. 
Each sloping dipole is feed with RG8X that is pulled away and attached to the
tower at 70 feet, and the lower legs are folded back toward the tower base.  The
8X is connected to separate 550 foot runs of 7/8 inch hard line running back to
the station building located to the northwest.  Minor pruning of the ground
level element halves yielded excellent 1.2 to 1 SWR readings at the 1830 design
frequency on both slopers .  Computer models predict 5 dB of gain in the
direction of the sloping dipoles.  We can switch to either primary direction, or
combine both driven elements together for an omni-like pattern.  On the air
comparisons with the inverted L reference antenna 500 feet away have confirmed
the computer model gain figures, and then some.  This is by far the best 160M
antenna system we’ve ever used, and it has the advantages of being relatively
easy to erect (of course having a very tall tower available isn’t all that easy
to find), simple and non-critical adjustment, the antenna  doesn’t require a
radial system, and the price tag is exceptionally low compared to alternatives. 
(We sincerely thank K3LR, and K1VR for ideas which lead to this design).

While the antennas were being repaired outside, our station configuration
specialists were hard at work cabling three transceivers, two amplifiers, four
computers, and antenna switching systems in the station building.  An IC756ProII
and Alpha 87A were installed at the run position, with an  IC746 slave receiver
alongside.  The multiplier position was an IC765 and AL1200.  All six beverages
and a transmit antenna can be selected by either station through custom switch
boxes.  The slave receiver can select from 4 beverages (NE, W, S and SW). 
During operation the slave receiver tuned to the run frequency to provide
reception diversity which we’ve found to be  essential due to “cone of silence”
beverage performance….we don’t want to miss anyone calling from any direction. 
A transfer switch allows instant swapping of transmit antennas between run and
mult positions.  Another switching system provides the ability to fire the
sloper array NE, SW or combined for omni coverage.  A keying interface provides
convenience plugs for several different paddles, and an electronic lockout
switch to ensure only one signal is on the air at any time.  The computers are
networked and we run CT logging software.  Even the casual observer would say we
threw away all  KISS rules when designing this station configuration.  It’s a
complex maze of wires and connections.  


Final Adjustments and Contest Operation

Upon return from the marsh after making repairs to both TX antennas, additional
testing was performed to see what could be done to reduce the high level of RF
in the shack.  W2NO had put together  3 of the solenoid RF chokes discussed
earlier.  We installed one at the Inverted L feed point behind the 4:1 unun.
This seemed to have some positive benefit, there was less SWR change when we
switched to the South Beverage which unfortunately is located in the near-field
of the Inverted L.  We then put one, and later two chokes in series with  the
South Beverage feed line.  This nearly eliminated the observed interaction, but
not entirely.  As a final step, we added a 150 foot coil of RG213 to the
beverage line.  Bingo, the interaction nearly disappeared completely.  Before
CQ160M, we’ll relocate the south beverage.

Tuning the band about an hour before sunset we heard several Europeans running,
the loudest by far was GU4YOX….an amazing S-9+10 on the NE sloper– simply
booming!  Switching to the SW sloper we saw almost 20 db of signal drop and in
the omni position the signal was roughly 6 db lower than when listening NE. 
Another comparison of the Inverted L to the NE sloper array produced about the
same difference, roughly 6 db, confirming the model predictions.  All of this
was quite encouraging. 

We decided to start operating just before sunset at 2130 Z and quickly had a
nice pileup  of both EU and stateside.  The run station was kept on the NE
sloper array about 90% of the time over the next 9 hours until EU sunrise.  At
times switching to the array’s omni position improved the overall rate with more
US stations calling in.  At the same time we had to be very attentive to RX
antenna selection, the two element phased EU beverage array was exhibiting
extreme “cone of silence” performance, W’s were inaudible.  The slave RX
operator kept vigilance for W’s using the South and West beverages.  

We started and ended the contest on 1821.4, logging 43 stations in the first 30
minutes (12 Europeans among the 43) and 84 after 60 minutes (with another 9 EU,
and 5B4AGN).  Conditions to EU seemed very good in the early going, signals were
generally loud and easy to copy.  The second hour continued this trend, 50 more
contacts, 27 from EU and 1 AF.  Hour three was almost a carbon copy, another 50
contacts, 27 EU and 4X3A.  We felt LOUD, and began to expect the string of DX to
continue unabated 

But it was not to be.  During the fourth hour the string of Europeans calling
simply dried up.  While the rate jumped to 74 QSOs this hour, only 4 were EU.  
Hour five the rate dropped back to 40 with another  4 EU, most of which were
quite weak, with heavy QSB, and signals had a meteor scatter quality to them. 
It often took 3 sets of ears to piece together the call and report.

The next hour conditions to EU vastly improved.  Just another 36 contacts were
logged, but more than half were from across the pond, most of them from far
Eastern Europe where sunrise was approaching.  And at the same time conditions
to the western US were coming up nicely too.  Hour seven we added still another
39 Q’s of which 17 were EU, and 4 or 5 from CA, OR and other western states. 
The points were really starting to add up with a very nice percentage of 2000+
km QSOs.

The dash through EU sunrise the next two hours was a real blast.  The percentage
of EU stations worked jumped dramatically – the band was showing the effects of
fewer sunspots.  G3SED finally closed the book on EU at 0905 Z.  When the smoke
cleared we had 203 European, Asian and African calls in the log, far exceeding
all pre-contest expectations.  Maybe we were just in the right place at the
right time with antennas that work.  

Then the last few hours reminded us of SS CW on Sunday afternoon.  Lots of F1 in
repeat mode between short breaks.  Operator “error” at sunrise blew our chance
to work one or more of the VK’s and KH6….next time!

We finished the SPTC very pleased with the team’s overall effort, and the
performance of our FD station by the sea after all of the antenna repairs and
other improvements.  Special thanks to NO2R, KU2C, KA2JAQ, W1GD and members of
the OBARC radio club for their help and support.  See everyone next month in
CQ160M CW.  HNY !!!!!

73, John W2GD/P40W 
w2gd at hotmail.com


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