[DX] dipole vs horiz. loop for low band DXing

Mon, 4 Nov 2002 12:13:14 EST

In a message dated 11/4/2002 11:15:47 AM Eastern Standard Time, [email protected] 
writes:

> See any good Antenna Book such as the ARRL
> Antenna Handbook for ground reflection coefficents
> vs height and plots of horizontally polarized antenna
> patterns in the vertical plane.
> 

The older ARRL Antenna Handbook I have leads off the lowband section with 
just such an antenna called the "Skywave Loop"     While, yes, it is a high 
angle radiator, it is a very effective antenna for the limited antenna ablity 
DXer.  First is that it has gain over a dipole and because of its closed loop 
and less than 1/2 wave above ground will be a much quieter antenna on 
receive.  

Our Field Day site has several wooden poles 100 feet apart.  A triangular 
section was taken for the perimeter of our 80 meter loop, 285 feet hung 
inside.  This was our best 80 meter antenna for FD.  Going up with ease, it 
was used Friday evening for fun.  QSO's from NJ to Europe were plentiful and 
reports exclaimed disbelief that we were portable and only using 100 watts.  
Moderate DX distances such as Europe, west Africa, Caribbean, and South 
America were easy pickings.  Longer DX to the Pacific and Asia was harder, 
but workable.

The antenna was used on the higher bands effectively.  Contrary to many 
reports, the loop was fed directly by 50 ohm coax as stated in the ARRL 
article.  Many DXers insist on baluns and tuning stubs.

Personally I use a vertical on 80 meters.  I have several radials made of 3/4 
CATV hardline stretched through the woods.  It plays great and does just what 
a vertical for 80 meters should.  The problem is, it radiates too low.  The 
amount of stateside and moderate distance DX that it can't work is at times 
frustrating.

While not purely the best, the loop asked about is a good move.  It covers a 
much more active field of interest in most operating and does not need the 
switching of feed locations as vertical delta loops for polarization changes.

While antenna modeling is a science, the actual designs of each installation 
for the intended purpose of the user is where the "art" lies.

============================================================
     Bob Reed, W2CE       
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 [email protected]       [email protected]     [email protected]
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