Topband: Pratus Is....A Quick Summary

[W9zr@aol.com]

Hi Topbanders

I just returned last evening from a long and exhausting trip from Taiwan 
<Pratus Is>.  Three days travel each way including air, car, and military 
flights.  I thought you would be interested in an explanation as to why more 
160 QSO's were not made.

By way of background Pratus is an island in the South China Sea owned by 
Taiwan.  It is an active military installation and access is very tightly 
restricted.  Our operation was almost cancelled at the last minute because of 
the current tensions between Taiwan and PRC.  The island is about 2km by 4 km 
and has no vegetation higher than about 10 feet high because of regular 
typhoons.

I was a last minute addition to the team.  I was to operate primarily CW and 
concentrate on 30, 40, 80 and 160 meters where there have been very few QSO's 
made in the past.  Since my first love is 160 I would need to balance 
activity on topband with the need to give out a lot of Q's on the other 
bands.  In addition, since it was so late in the topband season I realized 
that propagation and QRN could really cause some serious problems.

I came equipped with everything needed for multiple beverages.  The map of 
the area indicated that there were some wide open spaces around the shack so 
that beverages would not be a problem.

The transmit antenna was a Titanex V160 E, about 90 feet high with a match 
box for 40, 80, 160.  It would be mounted on the beach.

The Amp was a MLA 2500, courtesy of W8UVZ , and it was to put out a KW.  
However, due to voltage sag from the generator it never put out more than 500 
watts

Well, so much for the plans!!

It turns out that the area around the shack is surrounded by roads with lots 
of military traffic.  Also the vegetation on the island is so thick that it 
is impossible to walk through or around in order  to string a beverage.  In 
hindsight I should have brought a bow and arrow to launch the beverages over 
this crud.  Without beverages this late in the year and so close to the 
tropics things did not look good.

On to the Titanex.  This was my first experience with this antenna and it is 
not real easy to install.  Ideally you would have calm condx and a 
coordinated crew.  Unfortunately, the wind was howling the first 3 days of 
our operation and I decided to try to install it anyway.  In addition our 
crew was made up of some who spoke English and some who spoke Chinese.  You 
guessed it....the vertical came crashing down and in fact came close to 
seriously injuring one of our crew.

This happened after many long hours of working in the hot sun installing 5 
beams for the higher bands.  I was jetlagged, dead tired, had a pinched nerve 
in my neck, and was really discouraged.

I decided to take an hour and just lie  on the cot and contemplate the low 
band antenna situation a bit while I calmed down!

Since I was not satisfied with the planned 30 meter antenna, a linear loaded 
dipole at 15 feet, this band had to factor into my plans as well.

After thinking of the alternatives I decided to remove the bent sections of 
the vertical and to make it 70 feet high.  This would be 3/4 wave on 30 so a 
direct feed would be possible along with a small amount of gain, 80 would be 
fed directly as a full size 1/4 wave and 160 would need a new tuning unit.  
40 was eliminated since we were able to get a 2 element Cushcraft up about 35 
feet.  To enhance 160  I decided to double the number of radials to 40 from 
20.

The 160 tuning unit was a hay wired affair with alligator clips , etc but 
appeared to match ok.  The big drawback was that changing to 160 required a 
trip to the base of the vertical on the shore to change feedlines each time.  
Since this was in a restricted area I was hestitant to do this often but as 
the week went by I grew bolder and made the trip more than 100 times!  The 
antenna appeared to work well on all bands based on the reports.

On the first day of operations condx were quiet and I felt that the lack of 
beverages wasn't going to be a problem.  Propagation was excellent and I 
easily worked all the way across the US on 80 at my sunset with good signals. 
 The 160 matching unit was not ready yet so I concentrated on 80 and 40 with 
very good results.  The vertical was really playing well on 80 and I was 
really hopeful for 160 in the coming days.

Unfortunately, a major solar storm happened on day 2 which really killed the 
low bands for the next 2 days.  In addition storms started brewing in the 
area which raised the QRN to 30 over.  I called CQ on 80 and 160 at  the 
right times for Euope and NA with very few takers on even 80 meters.

On day 4 things starting looking up and I again could work Eu and NA on 80.  
However with the QRN 30 over all the time the only stations that I could hear 
on 160 were JA's.  I also worked 9V, 9M, VK's, VR2, YB, KH2,HL,UA0's on 160 
but no Eu or NA.  I also was plagued by very loud fish buoys.  These things 
are everywhere in this area as this is premier fishing grounds.  They are 30 
over 9!!

On day 5 I heard KA6W with a great signal at his sunrise but I could not load 
the vertical.  I have been bothered by an intermitant problem and I thought 
it was the tuner.  After messing with the problem for 3 days I finally 
discovered a bad barrel connector.  Grrr!  

On the last day the noise was still 30 over so I decided to put up a beverage 
even though it was not really pointed on Europe at all.  I figured it was 
better than nothing.  Lo and behold I could finally hear a few signals.  Even 
on the beverage the noise was S9 but it made just enough difference and I was 
able to work 20 European stations.

In total about 250 topband QSO's were made, mainly with JA.  I listened for 
JA on 23 since they now have the new freqs and then would ask them to QRX 
periodically so that I could see if other regions were coming through.  This 
appeared to work very well and as long as they have the discipline to stand 
by when requested this procedure should really help the JA's work DX in the 
future.

While this was not a very successful topband operation, I gave it a maximum 
effort.  Even though this was late in the season, I knew that this would be a 
rare opportunity for a dedicated topbander to be active from Pratus and I 
wanted to be as active as possible. Without beverages and plagued with 30 
0ver 9 QRN there was just no way that I was going to hear weak signals.  Had 
we been there even 4 to 6 weeks earlier I am sure things would worked out 
much better.

73 

Randy W9ZR






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