"Owen Duffy" wrote in message
...
"Jerry" wrote in
:


"Owen Duffy" wrote in message
...
"Jerry" wrote in
:

...
Hi Owen

Richard Clark once told me how to combine 4 antennas in an array.
He got
me to feed 4 antennas, 50 ohms each with 50 ohm coax with no
dividers.
I just fed each antenna with 50 ohm coax. At the point where the
4
coaxes get combined, I connected two coaxes in series and the other

Can you explain in more detail what you mean by "I connected two
coaxes in series"?

two also in series. Then parallel them to get back to 50 ohms.
The result is two 50 ohm loads in series to make 100 ohms and with
the other 100 ohms in parallel, the combination is a good 50 ohm
load. You can see a sketch in the Feb 2008 QST. It works pretty
slick when the antennas are 50 or 70 ohms where it is easy to get
the right coax impedance.

Owen

Hi Owen

I dont know how to include pictures in this text.

I would draw two touching circles to represent the outer conductors.
The
generator is fed between to the inner conductors. Hence, two 50 ohm
loads on the coaxes will look like a 100 ohm load to the generator.

Jerry

Ok, I understand, you the two inner conductors with a 100 ohm load
between them.

You have another pair like that from the other two arrays.

How do you connect them to the main feedline.


Owen

Hi Owen

The two 100 ohm loads in parallel give a 50 ohm load to the 50 ohm coax
main feed line. I used a ferrite "balun" where the unbalanced 50 ohm
*main feed line* connects to the center conductors that are connected to be
a 50 ohm load. .

Jerry KD6JDJ