On Jun 28, 4:51*pm, Owen Duffy wrote:

I had a look at your model and couldn't make head and tail of it.

Owen, maybe the following description will help with understanding my
model.

The antenna is an OCF Dipole in a Vee configuration. Wires 1 and 3 are
the short and long sides respectively. Wire 4 is just a short
connector at the apex. The antenna is fed with 100 feet of 450 ohm
line which transitions through a 4:1 transformer to 5 feet of 50 ohm
coax and then to the source. Wire 6 is an attempt to simulate the
unbalance radiation from the 450 ohm line. Wire 7 is an approximate
80m 1/4 wave RF "sink" on the ground side of the source end of the
model and is not meant to be a main element radiator so its position
relative to the other elements is immaterial.

Also, as you can see, I have wire 6 grounded which isn't actually the
case in the physical world. It is meant to simulate radiation from the
450 ohm line which actually ties into the 200 ohm (ungrounded high Z
side) of the transformer. I guess I figured grounding it was the right
thing to do since the EZNEC Help file implies the need for that to
simulate coax radiation. I do have wire 6 positioned correctly
relative to the other antenna elements, so its effect on the antenna
pattern should be accurate.

Don't let short wire 5 which looks out of position throw you. It just
serves as a termination junction between the 50 ohm side of the
transformer and the short run of coax. There are a couple of other
short "junction only" wires in the model.

A look at the wires, transmission lines, transformers, and sources
tables should aid in understanding the model.

I by no means mean to imply I've modeled everything correctly. I just
wanted you to know what I was attempting when I built the model.

Thanks for the Carolina Windom model. Good reference for comparing to
what I have done.

Also, thanks for looking at this. Any advice much appreciated.

73

Dykes (AD5VS)