Re: [HCDX]: Beverage matching/tuning/balun

[Jorma Mantyla <jmantyla@xxxxxxxxxxxxxxxx>]

A description of my antenna system can be found at
	http://www.kaapeli.fi/~jmantyla/eng.htm
	http://www.kaapeli.fi/~jmantyla/kartta.htm
I have been using many years 3 Beverages which are relatively short:
around 200 metres (220 yds).  However, I have found that the effect
of the resistor at the end of the antenna (around 500 ohms) is very
positive: a 200 metre Beverage is clearly better than a 200 meter
longwire without the resistor.
However, the full effect (sensitivity&directivity) of a Beverage antenna
is achieved only when the antenna lenght is 1-2 x wavelenght.  On 600 kHz
that is 500 metres x 2 = 1000 metres = 1 kilometer.  The minimum
is 1/4 of wavelenght, on 600 kHz it is 125 metres.
I agree agree with Patrick Martin.  A coaxial wire is needed
to get the signal into the house. I use 75 ohm coax.  
However, another important point is GROUNDING.  If you want the
Beverage to work you need good grounding at both ends of the antenna:
the resistor at the end of the antenna must be grounded in wet, swamp
ground using a lot of copper.  You need to dig.  The other wire of the
coax must be grounded well, too.  With good grounding you can use long
coaxial wires without loss of signal strenght.
The result is that you get rid of man-made noise near buildings etc.
Then you need an antenna tuner and/or a preselector.  With these
tools the Beverage antenna really works, and the effect is ...
crushing.  A 1000 metre Beverage is like a vacuum cleaner, you get
dx-stations exactly from the direction of the antenna while most
interfering stations are nulled out.

Jorma Mantyla
Kangasala
Finland
jmantyla@xxxxxxxxxx
http://www.kaapeli.fi/~jmantyla/

------------------------------------------------------------------------
This is a message from Jorma Mantyla <jmantyla@xxxxxxxxxxxxxxxx>
to hard-core-dx@xxxxxxxxxxxxx list. To unsubscribe the list, send
"unsubscribe hard-core-dx" in mail body to majordomo@xxxxxxxxxxxxxx
For more information, please check http://www.iki.fi/rko/hard-core-dx/
or email Risto Kotalampi, risto@xxxxxxxxxxxxxx
------------------------------------------------------------------------