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Old November 27th 04, 01:02 PM
Volker Tonn
 
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Lucky schrieb:

"Volker Tonn" wrote in message
...


RHF schrieb:


You may wish to consider moving the Feed-Point from the Center of Two
Equal Arms to an Off-Center Feed-Point with a Short-Arm of 38% and a
Long-Arm of 62% of the Total Length of the Antenna. This type
'configuration' of Wire Antenna is called a "WINDOM" Antenna.


It's more likely a FD-Antenna. This is fed with a coax-cable and a 1:4
BalUn.
A real[tm] windom antenna is fed by a single wire feeding the "top of the
asymmetric T" without a BalUn. The windom Antenna is much more limited in
bandwidth compared to a FD-antenna.
The BalUn of a FD-Antenna you can feed with some more different wires of
different lenghts. Try some additional shorter wires to increase reception
on the higher bands. I feed mine with 4 wires of app. 8, 20, 45 and 120ft
paired 120 and 8 ft on one connector and 45 and 20ft on the other
connector of the BalUn with very good results from 10 to 80 meters. It
even works fine as CB-antenna with low SWR.



Hi

So you're saying add extentions to the ends of the ant not near the balun??
I'm not using coax cause the radio is right near the window on a table. The
twinlead comes in, gets hooked right up to the balun, and then 50Ohm coax
rest of the way to the to the radio. I'm using 40 FT total for that's all I
have room for but I can add the extentions. What lengths would you suggest
for each end?

I don't understand where and how I add more then 2 wires to it. At what
points do I add them to? How do you use 4 wires?


One picture explains more than 1000 words :-)
Use monospaced charctars please.
Feel free to modify the picture to explain your own setup.


8ft | / 120ft
| /
|/
0 wire connector on BalUn
coax-feed |-|-|
==============0| |
|-|-|BalUn 1:4
0
|\
| \
20ft | \ 45ft

For sure you can use a twin-lead 300 Ohm wire going off the balun and
then feeding the antenna wires of different lengths. This 300-Ohm wire
works like a ladder-line -just not a very good one though-.
Best setup is to connct the different wires directly to the BalUn. No
matter if the wires are somewhat in parallel a few feet as the wires
allways will interact some way.
Did you have the 300-Ohm wire split on the far end? This is somewhat
essential to get good signals.