Hi

I was given a Omni antenna from a ham who claims the best thing since sliced
cheese. I want to use it for receive at first and when licenses come in for
transmit. I would like to transmit on as many frequencies as practical and
possible as I have a good tuner.
This is an omni, aluminum, telescopic and it 19 feet long. It has 4 ground
planes about 8 feet long.
As I was cleaning it up, I noticed a coil at the base of the antenna
connecting ground to center. Right at the female connector within the base
of the antenna. There is a coil that has approx 20 windings and connects to
ground. The center also feeds to the piping that stretches the full 19 feet.
The coil is pretty rough shape.
My question is in regards to this coil. Is it necessary? What function will
it serve? I can rebuild it if need be but is that necessary? And is 19 feet
a good length for utilizing as many useable frequencies as possible?
Any advice?
Thanks
Bob

That antenna needs the coil. That antenna is specifically designed (I
would guess) for a specific frequency (more like a band .. say 2 meters)
You will not likely be able to use it to transmit on bands that it was not
designed to transmit on (6 meters, 440, 220, 80meters and so on)

The closest thing I know of for a omni-directional multi band UHF/VHF
antenna is the DISCONE type of antenna (Radio Shack sells one, Diamond
sells a very nice one as well)

Richard in Boston, MA, USA

Bob wrote:
: Hi

: I was given a Omni antenna from a ham who claims the best thing since sliced
: cheese. I want to use it for receive at first and when licenses come in for
: transmit. I would like to transmit on as many frequencies as practical and
: possible as I have a good tuner.
: This is an omni, aluminum, telescopic and it 19 feet long. It has 4 ground
: planes about 8 feet long.
: As I was cleaning it up, I noticed a coil at the base of the antenna
: connecting ground to center. Right at the female connector within the base
: of the antenna. There is a coil that has approx 20 windings and connects to
: ground. The center also feeds to the piping that stretches the full 19 feet.
: The coil is pretty rough shape.
: My question is in regards to this coil. Is it necessary? What function will
: it serve? I can rebuild it if need be but is that necessary? And is 19 feet
: a good length for utilizing as many useable frequencies as possible?
: Any advice?
: Thanks
: Bob

That antenna needs the coil. That antenna is specifically designed (I
would guess) for a specific frequency (more like a band .. say 2 meters)
You will not likely be able to use it to transmit on bands that it was not
designed to transmit on (6 meters, 440, 220, 80meters and so on)

The closest thing I know of for a omni-directional multi band UHF/VHF
antenna is the DISCONE type of antenna (Radio Shack sells one, Diamond
sells a very nice one as well)

Richard in Boston, MA, USA

Bob wrote:
: Hi

: I was given a Omni antenna from a ham who claims the best thing since sliced
: cheese. I want to use it for receive at first and when licenses come in for
: transmit. I would like to transmit on as many frequencies as practical and
: possible as I have a good tuner.
: This is an omni, aluminum, telescopic and it 19 feet long. It has 4 ground
: planes about 8 feet long.
: As I was cleaning it up, I noticed a coil at the base of the antenna
: connecting ground to center. Right at the female connector within the base
: of the antenna. There is a coil that has approx 20 windings and connects to
: ground. The center also feeds to the piping that stretches the full 19 feet.
: The coil is pretty rough shape.
: My question is in regards to this coil. Is it necessary? What function will
: it serve? I can rebuild it if need be but is that necessary? And is 19 feet
: a good length for utilizing as many useable frequencies as possible?
: Any advice?
: Thanks
: Bob

As Richard suggested, I'd recommend a discone antenna for multi-band
VHF/UHF operation, although you can purchase other types that will provide
better performance on 2M and the 440 ham bands. That antenna you have
sounds, to me, like a CB antenna and probably is not appropriate for
anything except possibly the 10M ham band.



Ed WB6SAT

As Richard suggested, I'd recommend a discone antenna for multi-band
VHF/UHF operation, although you can purchase other types that will provide
better performance on 2M and the 440 ham bands. That antenna you have
sounds, to me, like a CB antenna and probably is not appropriate for
anything except possibly the 10M ham band.



Ed WB6SAT

"Bob" wrote in message ...
Hi

I was given a Omni antenna from a ham who claims the best thing since sliced
cheese. I want to use it for receive at first and when licenses come in for
transmit. I would like to transmit on as many frequencies as practical and
possible as I have a good tuner.
This is an omni, aluminum, telescopic and it 19 feet long. It has 4 ground
planes about 8 feet long.

Thats a 10-11 meter 5/8 ground plane...It can be used for casual
receiving, but how well it works will depend on the bands you use it
on. Naturally, it would be good for CB or the 10m ham band, and
probably receive ok on the higher HF ham bands, but for VHF/UHF , it
will be fairly lame. It's too long...You can try it though...

As I was cleaning it up, I noticed a coil at the base of the antenna
connecting ground to center. Right at the female connector within the base
of the antenna. There is a coil that has approx 20 windings and connects to
ground. The center also feeds to the piping that stretches the full 19 feet.
The coil is pretty rough shape.



My question is in regards to this coil. Is it necessary? What function will
it serve?

Thats the loading coil to tune the 5/8's radiator to a 3/4 wave
resonance. That gives a good match to coax.. On the band it's designed
for, that is...

I can rebuild it if need be but is that necessary?

No. Not unless it's broke..

And is 19 feet
a good length for utilizing as many useable frequencies as possible?

19 ft is appx a 5/8 wave on 10/11 meters..That antenna is designed for
a single band. It's usable for casual listening on the HF bands. You
don't really need too good a match there in order to have a decent s/n
ratio. MK

"Bob" wrote in message ...
Hi

I was given a Omni antenna from a ham who claims the best thing since sliced
cheese. I want to use it for receive at first and when licenses come in for
transmit. I would like to transmit on as many frequencies as practical and
possible as I have a good tuner.
This is an omni, aluminum, telescopic and it 19 feet long. It has 4 ground
planes about 8 feet long.

Thats a 10-11 meter 5/8 ground plane...It can be used for casual
receiving, but how well it works will depend on the bands you use it
on. Naturally, it would be good for CB or the 10m ham band, and
probably receive ok on the higher HF ham bands, but for VHF/UHF , it
will be fairly lame. It's too long...You can try it though...

As I was cleaning it up, I noticed a coil at the base of the antenna
connecting ground to center. Right at the female connector within the base
of the antenna. There is a coil that has approx 20 windings and connects to
ground. The center also feeds to the piping that stretches the full 19 feet.
The coil is pretty rough shape.



My question is in regards to this coil. Is it necessary? What function will
it serve?

Thats the loading coil to tune the 5/8's radiator to a 3/4 wave
resonance. That gives a good match to coax.. On the band it's designed
for, that is...

I can rebuild it if need be but is that necessary?

No. Not unless it's broke..

And is 19 feet
a good length for utilizing as many useable frequencies as possible?

19 ft is appx a 5/8 wave on 10/11 meters..That antenna is designed for
a single band. It's usable for casual listening on the HF bands. You
don't really need too good a match there in order to have a decent s/n
ratio. MK