Windom/OCF antenna question
 

Hi Group,
I am planning to place a wire multiband, 50ohm coax feed, based on
plans found on Buxcom. His is for 80m and up, I dont have that kind of
room so used his formula to generate a 40m and up. My question is about
matching the impedence. His 80m uses a 4:1 and assumes placement higher
than 20 feet.
I cant get the whole thing over 20 feet, but I can get part of it over
20. The antenna will start off on my roof peak (13 feet tall) then
angle out at about 40 deg to a tree.
I cant model this so I have to ask, can I still use the 4:1 or will I
need something else?
Thanks for any guidance!!

"DaveC" wrote in message
oups.com...
Hi Group,
I am planning to place a wire multiband, 50ohm coax feed, based on
plans found on Buxcom. His is for 80m and up, I dont have that kind of
room so used his formula to generate a 40m and up. My question is about
matching the impedence. His 80m uses a 4:1 and assumes placement higher
than 20 feet.
I cant get the whole thing over 20 feet, but I can get part of it over
20. The antenna will start off on my roof peak (13 feet tall) then
angle out at about 40 deg to a tree.
I cant model this so I have to ask, can I still use the 4:1 or will I
need something else?
Thanks for any guidance!!


A 6:1 balun is usually beter for an OCF antenna. They are harder to make
and come by. That is one reason a 4:1 is often used.

DaveC wrote:
Hi Group,
I am planning to place a wire multiband, 50ohm coax feed, based on
plans found on Buxcom. His is for 80m and up, I dont have that kind of
room so used his formula to generate a 40m and up. My question is about
matching the impedence. His 80m uses a 4:1 and assumes placement higher
than 20 feet.
I cant get the whole thing over 20 feet, but I can get part of it over
20. The antenna will start off on my roof peak (13 feet tall) then
angle out at about 40 deg to a tree.
I cant model this so I have to ask, can I still use the 4:1 or will I
need something else?
Thanks for any guidance!!


Hi Dave,

You should find that the antenna will work well for you except perhaps
on 15m I have a very similar set up here and it works great.. Unlike he
says on the Buxcom site though you will most likely need a choke balun
1:1 in the line to keep RF out of the Shack, Mine is similar to the
Carolina Windom in that I placed a Choke balun about 30 feet down the
feed line .. works quite well..
73 Dave kc1di