"JIMMIE" wrote in message
oups.com...
Plan is to build a J antenna for 20 meters using 1 inch EMT conduit.
Antenna will be supported at the bottom by a 4x4 post in the ground and
at the 30+ foot level with a fiberglass bracket bolted to the eve of
the house. The upper most section will be a fiberglass 1/2 wl antenna
thta used to be used for CB. I am looking for a program that will allow
me to calculate deminsions for a project like this. Feedline will be 50
ohm coax.

Why not build an end fed 1/2 wave antenna and forget about the mechanics of
the 1/4 wave matching section and the problems of its height? IMHO, a simple
L or Pi network in a WX proof box with a 33' vertical would be a lot easier
to construct and adjust than a 50' tall antenna.

Dale

On Mon, 23 Jan 2006 14:36:51 GMT, "Dale Parfitt"
wrote:

Plan is to build a J antenna for 20 meters using 1 inch EMT conduit.
Antenna will be supported at the bottom by a 4x4 post in the ground and
at the 30+ foot level with a fiberglass bracket bolted to the eve of
the house. The upper most section will be a fiberglass 1/2 wl antenna
thta used to be used for CB. I am looking for a program that will allow
me to calculate deminsions for a project like this. Feedline will be 50
ohm coax.


Yes, I may I suggest you take a look at this one. You'll get two bands
instead of one.

http://k6mhe.com/files/DualBandVert.pdf

Danny, K6MHE




email: k6mheatarrldotnet
http://www.k6mhe.com/

The associate ground system is not practical at this location

"JIMMIE" wrote in message
oups.com...
The associate ground system is not practical at this location

What associated ground system are you referring to?