Topband: Soliciting suggestions on our receive antennas for 5X8C

[Tom W8JI]

> So put you're receive antenna hat on.  We suspect the ground is the 
> problem.  We are located on the shore of Victoria Lake at a resort.  The 
> soil appears to be sandy but with fresh water lake nearby. 200 feet.  The 
> beverage is in the clear away from large metal objects.
>

Fresh water has poor conductivity. It is like bad dirt, unless salty. Even 
with salt water, the antennas would not make noise, and they would hear 
something.

> With a 510 ohm termination we measure about 235 ohms when looking across 
> the termination resistor.  Using resistor theory essentially we have two 
> resistances in parallel.  The wire , termination transformer, ground rods 
> and ground are about 500 ohms.  Having not measured this at home I'm not 
> sure if this is too low or too high of resistance.
>

It is difficult to measure anything that way, because any common ohmmeter 
will read the voltage bias of the earth and ground rods. This will throw off 
any reading.

Plus even if the terminations were bad, it would not cause what you 
describe.

I would look at feedlines and the radio, and the transformer at the 
feedpoint. I hope you are using an isolation style of transformer.


> We erected a Flag 29x14 feet mounted just above the ground.  This is 
> purported to be ground independent.  Our tests last night indicate this 
> antenna is not hearing very well either.
>

No antenna near earth is ground independent, although some antenna types do 
not use the earth as a connection point. Any antenna we install near earth 
will always be earth dependent, even if we have no earth connection.

I doubt that it is the earth, however. The Flag works increasingly better 
with higher conductivity earth, while the Beverage works worse. Even if you 
had a case where the earth conductivity was too good for a Beverage, a Flag 
antenna would actually be better than over poor earth!

The fact an antenna that likes better earth does not work, and one that 
likes poorer earth also does not work, re-enforces the idea that it is the 
feedline or radio or something other than the antenna.

> We are soliciting suggestions.  We only have a small amount of wire and 
> other antenna stuff, no Home Depot or Radio Shack around.  Perhaps we can 
> build a ground independent antenna that does not care what it sits on.


The only antenna that does not care what it sits on is one that is in space 
many wavelengths from earth.
:-)

You have a local problem with a local noise generator, or a problem in the 
radio or feedline.

73 Tom