Topband: Beverage Questions

[Don Kerouac]

Over the past couple of decades I have built many single and two wire
Beverages.
 
I have settled on dual direction two wire Beverages about 500-600 ft
long.  I have three of them giving me 6 directions.  I'd like a fourth
but I don't own the land!  :-)
 
I have used:
Two discrete wires spaced about six inches apart.  
Very poor quality 300 ohm TV twinlead.
High quality 450 ladder type line
 
There was absolutely no noticeable difference in the performance of the
above materials.  In fact the very poor quality 300 ohm TV line was the
easiest to implement and had the lowest wind load (whipping and
oscillating motions in the wind.another story)
 
I found some good quality brand name 300 ohm TV Twinlead at a good price
(clearance) and am in the process of replacing my old cheap line (it
won't work any better, the old line is simply failing).
 
Note:  Don't assume that just because you use 300 ohm line that the
impedance of the antenna will be 300 ohms.it likely won't.
 
I found out how well the balance to ground was when the ground
connection on the reflection transformer broke.  The antenna went
absolutely dead quiet in one direction while working fine the other
direction.
 
My experience is that the best performing, easiest to build transformers
(by far) are the ones using FairRite type 73 binocular cores.  Go to:
www.w8ji.com <http://www.w8ji.com/> 
and read all about them.
 
In general, the non-resonant nature of the Beverage antenna means that
there is very little coupling to other antennas nearby.  In fact, I have
one Beverage running over another separated by only inches.  Important
Gotcha:  If you run your Beverage near a resonant antenna (like your 160
transmit antenna) don't be surprised if your receive antenna performance
is compromised by noise re-radiated by your TX antenna.
However, if you place two Beverage designs parallel their full length
separated by only a few inches, don't expect to make any meaningful
comparisons.  That's way too much coupling.
 
Good luck and hope to work you on the band.
 
73, Don K9NR




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