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[TowerTalk] What about hams with small lots???

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Subject: [TowerTalk] What about hams with small lots???
From: (Tom Rauch)
Date: Sat, 1 Sep 2001 14:13:27 -0400
If you look at comparisons or honest reviews of small antennas for 
160 (or 80) meters, the most efficient ones are universally top 
loaded with some form of large hat or wire and employ reasonably 
large radial systems. 

That is why small "(almost) no radials required" verticals like the 
R7, GAP, MFJ and others often work OK on 20 meters or higher. 
They can be mounted so far above earth they are reasonably 
ground independent. But if we look at performance carefully, magic 
"no radial" antennas fall apart very quickly at lower frequencies!  

For example the MFJ "no radial" vertical and the GAP vertical are 
among the poorest low band verticals (40 meters and down) 
available, and of course antennas like the Sommer resistor-loaded 
vertical is the standard in poor low-band performance. 

The best 160 meter installations on small lots are universally 
inverted L antennas or some form of vertical radiator with top hats 
or top loading and the largest ground system that can fill the small 
yard. Other than that, a low dipole might as well be used.  

The worse installations are those with poor or non-existent ground 
systems and too many antennas in a small area, and fancy magic 
feed or loading systems.

Under-performing stations aren't the stations on small lots. They 
are the stations who try to stick too many antennas in a small 
area, or that rely on magic like asymmetrical feeds and "lossless 
loading" schemes and think that three or four radials .05wl above 
ground or less somehow does the trick.

Just when we think it can never get worse?

First we replaced inductors with Q's of maybe 200 or more with 
linear loading stubs with Q's of 40 or less, and called it an 
improvement. We have people convinced that 300 ohms of 
inductive reactance from a coil with a Q of 300 (one ohm loss) is 
less efficient than a 300 ohm reactance stub with a Q of 30 (ten 
ohms loss resistance)! 

The latest trend is to replace lossy loading coils and traps and 
even the stubs with pure 100% resistors and tell people by doing 
that they don't need a ground system at all and things get better! 
Now we have Q's of near zero, where reactance is near zero and 
loss resistance is 300, and the best ground systems are those 
with no radials at all. 

The twisted logic is with a loading coil or ground system you can't 
have loading coil or ground system loss, and so the electrical equal 
of dummy loads are being sold as superior!
73, Tom W8JI 

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