HF vertical using tower as groundplane?

[KB0UXV]

I was wondering if I could mount a Cushcraft ATV3 triband HF vertical antenna (10/15/20m) on a 30 foot Rohn galvanized steel tower and get a good ground plane from the tower alone? Thank you and 73, Nate in MN kb0uxv

[N2RJ]

What will happen is that your feedline's shield will act as a radial and that will lead to all sorts of problems.

It is better to cut some resonant radials (at least four per band) and use that. You can get a 1000' spool of wire for about $30 that will give you plenty radials.

[W5DXP]

Quote[/b] (kb0uxv @ Sep. 30 2007,04:48)]... a good ground plane from the tower alone?

The 30 foot tower is a half-wavelength on 20m. EZNEC says that such a configuration will result in a take-off-angle of 49 degrees on 20m, making it a cloud-warmer with not much DX potential. The radiation pattern on 20m is attached. A free demo version of EZNEC is available at http://www.eznec.com

[KB0UXV]

Thank you for the help. I am learning, just got the general upgrade. What gauge wire is best for the ground plane leads?

[W5DXP]

Quote[/b] (kb0uxv @ Sep. 30 2007,16:55)]Thank you for the help. I am learning, just got the general upgrade. What gauge wire is best for the ground plane leads?

Inexpensive #16 household wire from Home Depot is what I use for elevated radials that double as guy wires. It works best when the radials are electrically isolated from the tower. Some heights are better than others. The free demo version of EZNEC will yield a lot of information.

[K9FV]

#16 AWG for guy wires on a tower? Am I missing something there?

Ken H>