On Tue, 17 Jul 2007 14:58:58 -0400, "Ed Cregger"
wrote:


"Diogel" wrote in message
.. .
Hi

I have not had much success with a commercial tri band 6M/2M/70cm
vertical. I hope you know the type I am refering to, 2.5M high with
three radials, looks like two for 70cm and one loaded radial for
6M/2M.

I have never had any success with this antenna in the attic so did
some experiments with the antenna on a 8 foot glass fibre pole in the
garden. SWR and radiation were perfect until I rotated the antenna
with the loaded radial facing the house about 20 feet away, then SWR
climbs to 10:1 on 2M but is still perfect on 70cm ???. Not tried 6M
yet.

Any idears whats happening ?.

Tia

Dio


Your antenna sounds as though it is a Diamond V2000, or Comet equivalent. If
so, those are not radials, but decoupling stubs. Furthermore, the antenna
was designed to be mounted on a metal mast, not a non conducting mast. I
suppose you could run a length of wire alongside the non conducting mast to
give it the metal that it needs.

I suspect that your high swr situation has more to do with a loose connector
than with the decoupling stub pointing at the house (coincidence).

I used to operate with a Diamond V2000 some years ago and it did need to
have the mounting mast capable of electric conduction, IIRC.

Ed, NM2K

I have a bad case of vascular demensia, so take what I say with a grain of
salt.

Thanks Ed

I did'nt know they were decoupling stubs, I will try using a metal
mast tomorrow to see if there is any difference. Its odd that the 2M
part of the antenna is affected ?. I have just cleaned and reassembled
the antenna so am pretty sure all connections are solid.

Thanks for the info.

Paul