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

"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.

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

I have a 6m/2m/70cm Diamond V2000 and a 2m/70cm Workman (that looks a lot
like the V2000). I'm getting 2:1 @ 2m on both of these antennas. (1:1 @ 6m
on the V2000, I don't have an SWR bridge for 70cm).

My 2:1 sounds high, certainly 10:1 is too high.

Is anyone getting better than 2:1 @ 2m with the V2000?

--
Bob D. ND9B

"Ed Cregger" wrote in message
...

"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.

On Tue, 17 Jul 2007 20:57:27 -0700, Bart Bailey
wrote:

In posted on
Tue, 17 Jul 2007 20:54:19 +0100, Diogel wrote: Begin

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.

If the antenna had an acceptable SWR one time but now hasn't, you might
check the small capacitor located near the junction. That's what burn't
out in mine recently when overpowered. If you can see what value it is I
would appreciate knowing in order to get a replacement, mine's scorched
and shattered. I bought a new antenna and used the old 6m counterpoise
to have two of the three operable on 6m, wish I had a third for
symmetry.
I checked the antenna again, it consists of two steel rods coupled
together with a block of white insulating material which is bridged
with a coil. I can see no capacitor.
I tried mouning the antenna on an aluminium pole which made matters
worse. I notice that the antenna mountings are plastic so the antenna
base would be insulated from any mounting pole anyway.