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[3830] ARRL 160 W7TMT Single Op LP

To: 3830@contesting.com, w7tmt@dayshaw.net
Subject: [3830] ARRL 160 W7TMT Single Op LP
From: webform@b4h.net
Reply-to: w7tmt@dayshaw.net
Date: Mon, 8 Dec 2008 12:41:18 -0800
List-post: <3830@contesting.com">mailto:3830@contesting.com>
                    ARRL 160-Meter Contest

Call: W7TMT
Operator(s): W7TMT
Station: W7TMT

Class: Single Op LP
QTH: WWA
Operating Time (hrs): 26

Summary:
Total:  QSOs = 359  Sections = 64  Countries = 1  Total Score = 46,144

Club: Western Washington DX Club

Comments:

Propagation is the strangest stuff! Given the conditions on Topband in the week
or two preceding this years ARRL 160 I was optimistic. However, as it turned
out for me Mark Twain was right when he wrote that "The only thing worse than a
young pessimist is an old optimist". His observations about life were always
astute.

Preparations for this year's 160M events included a plan to get the boat out of
the marina and hopefully away from some of the noise sources. The worst emitter
disappeared when an old boat a couple of slips away left the marina. I suspect
he had an junk dime-store battery charger that was radiating a lot of trash.
Things are better now but there are still several of what sound like loud
switching power supplies there to clog up a few spots on the band especially
the top end of the DX window.

In order to keep my options open and not deal with the balloon I needed to come
up with a vertical antenna solution that didn't require a second support like my
inverted L at the dock does. The solution was to scale up (in length - down in
frequency) one-half of a linear loaded antenna design by K4VX
(http://www.arrl.org/tis/info/pdf/0207040.pdf) for an overall length of 90'.
The antenna described in the article produces a short 40 meter dipole. I simply
scaled it to 160 using the published 40 meter dimensions. Turned out it
resonated too low by a fair amount (1650 kHz) Trimming a little over two feet
off the linear loaded section brought it to resonate at the 1840 mark. 2-to-1
SWR bandwidth is barely 60 kHz so that's pretty good given the situation. I
reworked the fiberglass mast I hoist to the top of my 50' main mast and got the
upper end to just short of the 90' level. That long slender fiberglass section
really gets whipping around when the boat rolls (visualize the action of a good
fly-casting fishing rod) but it stayed all in one piece. (Perhaps I need to make
it longer.)

Friday morning I moved the boat over to the north end of Blake island. At that
location I have saltwater all around with no land closer than 2.1 miles at its
closest over most of the compass. The island only blocks from 170 to perhaps
210 degrees true. Plus the island is so low I doubt it matters since I was
anchored more than two wavelengths off-shore. 

One down side is that this is a very unprotected anchorage especially if it
blows out of the north but the weather guessers were saying no winds on Friday
night and out of the south at 10-15 on Saturday. The other negative, from an
anchorage perspective, is that it is exposed to the constant large ship traffic
in the sound. The big deep draft vessels headed south to Tacoma at 20+ knots and
the regularly scheduled Washington State ferry's headed to and from Rich Passage
on their way back and forth to Bremerton all provide for a pretty bumpy ride
more or less around the clock. But no sacrifice is too great for a dedicated
160 meter contester.

The real surprise was on the noise front. The junk from the surrounding boats
at the dock was replaced by intermod problems. It seems that the location is
perfectly triangulated between numerous high powered AM broadcast band stations
and given the clean open saltwater propagation path this was a problem. Even
with a W3NQN BCB filter inline (the one you can transmit through) I still had
intermod and this was with a K3 no less! This was something I hadn't expected.
Once I was there I decided to just go with it and pressed on.

Another negative about the location (that I had anticipated) was the proximity,
 just four open water miles to the east of me of three local stations all who
could probably see me if they looked out their window and that generally run
high power. With the K3 and 400 Hz. filter however, I thought "no problem".  As
it turns out there was a problem from one of them (who shall go nameless). The
signal strength was only about 20 over 9 but lot's of trash being generated up
and down the band none the less. The phenomena appeared on only one signal of
the two I heard and the other was actually stronger.

Friday night things sounded pretty good initially with my first mid-west QSO
appearing in the log at 1530 local time and the evenings final efforts were
only slightly down from last years rate. Saturday night was a different story.
High noise levels and weak and water signals from everything east of the
Rockies for much of the night. At times early Sunday morning even the big guns
like W8JI and K9DX were weak and watery. Additionally, their signals were
infused and/or modulated by atmospheric noise. The north east was nearly
non-existent and accounted for the majority of missing sections. From my
perspective conditions were not good.

I was 16 mult's and 170 Q's down for a score that's 39,936 points below the
winning LP WWA score in 2007. I guess that's part of the challenge.

I'm already looking forward to the Stew Perry Topband Distance Challenge at the
end of the month and have picked another anchorage for that event. Not quite as
much open water but perhaps a less noisy location.

See you in the Stew.

73,

Patrick, W7TMT


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