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Old February 4th 05, 12:58 AM
jimbo
 
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Default Flagpole/Vertical Antenna

Well, I found a reference to a 10-40 meter flagpole antenna for HOAs
that don't like antennas. But they all require radials as long as the
vertical height of the antenna, and my minuscule lot just won't be
large enough for radials of any significant size. Is there any other
option for a vertical antenna for 10-40 meters that doesn't require
radials?

In another location, I used a random length dipole under the eves of
the house with a Johnson Matchbox tuner with good results. And maybe, I
can do the same with a random length dipole in the attic, but the
flagpole is an intriguing option. And I was always concerned about the
radiation in the house from the antenna and from the ladder line lead.
In fact, the irrigation solenoid valves used to open when I
transmitted.

jimbo

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Old February 4th 05, 01:56 AM
Caveat Lector
 
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Well I may be wrong here but my understanding is the wires on the ground are
a counterpoise and need not be tuned. As they are coupling to the earth. But
it may take numerous wires for the counterpoise. Ground conductivity enters
into this as well.

Radials on an elevated antenna on the other hand should be tuned. Just four
radials on an elevated antenna will do well.

I had a ground mounted vertical and just sprinkled lots of wires thither and
yon as best I could to fit in the lot and the antenna tuned fine.

Try it and see the results.

You could try a half wave vertical -- no radials required but now you have
an impedance mathing problem.

Some Cushcraft antennas use a half wave end fed scheme, the black box at the
feed point is matching unit.
--
Caveat Lector (Reader Beware)



"jimbo" wrote in message
ups.com...
Well, I found a reference to a 10-40 meter flagpole antenna for HOAs
that don't like antennas. But they all require radials as long as the
vertical height of the antenna, and my minuscule lot just won't be
large enough for radials of any significant size. Is there any other
option for a vertical antenna for 10-40 meters that doesn't require
radials?

In another location, I used a random length dipole under the eves of
the house with a Johnson Matchbox tuner with good results. And maybe, I
can do the same with a random length dipole in the attic, but the
flagpole is an intriguing option. And I was always concerned about the
radiation in the house from the antenna and from the ladder line lead.
In fact, the irrigation solenoid valves used to open when I
transmitted.

jimbo



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Old February 4th 05, 02:40 AM
pfriedmanNoSpam
 
Posts: n/a
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"jimbo" wrote in message
ups.com...
Well, I found a reference to a 10-40 meter flagpole antenna for HOAs
that don't like antennas. But they all require radials as long as the
vertical height of the antenna, and my minuscule lot just won't be
large enough for radials of any significant size. Is there any other
option for a vertical antenna for 10-40 meters that doesn't require
radials?

In another location, I used a random length dipole under the eves of
the house with a Johnson Matchbox tuner with good results. And maybe, I
can do the same with a random length dipole in the attic, but the
flagpole is an intriguing option. And I was always concerned about the
radiation in the house from the antenna and from the ladder line lead.
In fact, the irrigation solenoid valves used to open when I
transmitted.

jimbo


Jim:

I suggest that you do not get carried away with not having room for "full
length" radials. I've read some interesting research (I will find the
references if you are interested) on this. It appears that radials as short
as 0.1 wavelength are quite effective. Are longer ones better. Yes. It is
also better to be transmitting in the middle of the ocean. It is better to
be young, rich, and handsome, too.

Seriously, lay down whatever radial pattern you can. The more the better,
the longer the better, but you will surprised how quickly (in both cases) it
becomes a matter of quickly diminishing returns.

A friend of mine lives in a restricted community in Southern Cal. He got
permission to put up a flag pole, so he and (I was visiting at the time)
went out on a Sunday afternoon when everyone could see us and set-up his
flagpole, raised the U.S. Flag, etc. Then, about 3 a.m. we went back out and
buried 4 radials and a coax feedline. There are not enough radials and they
are too short. However, he has no problem working the entire Pacific Rim
with 100w.

Paul AB0SI


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Old February 4th 05, 02:53 AM
H. Adam Stevens, NQ5H
 
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Default


"pfriedmanNoSpam" wrote in message
...
"jimbo" wrote in message
ups.com...
Well, I found a reference to a 10-40 meter flagpole antenna for HOAs
that don't like antennas. But they all require radials as long as the
vertical height of the antenna, and my minuscule lot just won't be
large enough for radials of any significant size. Is there any other
option for a vertical antenna for 10-40 meters that doesn't require
radials?

In another location, I used a random length dipole under the eves of
the house with a Johnson Matchbox tuner with good results. And maybe, I
can do the same with a random length dipole in the attic, but the
flagpole is an intriguing option. And I was always concerned about the
radiation in the house from the antenna and from the ladder line lead.
In fact, the irrigation solenoid valves used to open when I
transmitted.

jimbo


Jim:

I suggest that you do not get carried away with not having room for "full
length" radials. I've read some interesting research (I will find the
references if you are interested) on this. It appears that radials as

short
as 0.1 wavelength are quite effective. Are longer ones better. Yes. It is
also better to be transmitting in the middle of the ocean. It is better

to
be young, rich, and handsome, too.

Seriously, lay down whatever radial pattern you can. The more the better,
the longer the better, but you will surprised how quickly (in both cases)

it
becomes a matter of quickly diminishing returns.

A friend of mine lives in a restricted community in Southern Cal. He got
permission to put up a flag pole, so he and (I was visiting at the time)
went out on a Sunday afternoon when everyone could see us and set-up his
flagpole, raised the U.S. Flag, etc. Then, about 3 a.m. we went back out

and
buried 4 radials and a coax feedline. There are not enough radials and

they
are too short. However, he has no problem working the entire Pacific Rim
with 100w.

Paul AB0SI



I live in the sticks, so I can put up whatever I please.
But it seems to me a metal roof with a Fluidmotion SmallIR with a flag on
the roof would ROCK from 20 on up.
Of course folks who wanted just a flag have been screwed by homeowner's
associations.
OTOH a nice copper gutter can get the job done.
Or just build a kick-ass mobile rig.

BTW
Why do people even get involved with such BS, anyway?
I didn't make you live there.

73
H.
NQ5H


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Old February 4th 05, 01:35 PM
KC1DI
 
Posts: n/a
Default

jimbo wrote:
Well, I found a reference to a 10-40 meter flagpole antenna for HOAs
that don't like antennas. But they all require radials as long as the
vertical height of the antenna, and my minuscule lot just won't be
large enough for radials of any significant size. Is there any other
option for a vertical antenna for 10-40 meters that doesn't require
radials?

In another location, I used a random length dipole under the eves of
the house with a Johnson Matchbox tuner with good results. And maybe, I
can do the same with a random length dipole in the attic, but the
flagpole is an intriguing option. And I was always concerned about the
radiation in the house from the antenna and from the ladder line lead.
In fact, the irrigation solenoid valves used to open when I
transmitted.

jimbo

Hi Jimbo,

All the responses you have received so far are good, But one other
possibility is to install a fiberglass flag pole with a diameter big
enough to accomodate and R-7 or similar no ground vertical. A freind
here did that and it worked quite well.

73 Dave

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Old February 4th 05, 03:55 PM
Reg Edwards
 
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Long, shallow buried radials are by no means a necessity.

Your dry, painted timber flag-pole, with a plastic insulated antenna wire
running down it, can be located alongside a wall of your house or at the
end, side or middle of the garden.

The soil should not be very dry and sandy but should be capable of growing
common-or-garden flowers, shrubs or lawn grass. To improve the soil dig in
compost or horse manure. A light sprinkling of copper sulphate won't do any
harm except perhaps to the plants.

Lay a dozen or a score of 10-gauge or thicker radials, as long as you can
and in as many directions as you can from the base of the pole. They will be
useful even if only 2, 3 or 4 feet long.

Use bare copper wire, at a depth of a few inches in well compacted,
trodden-down soil. Lay paving slabs on top if you like.

For multi-band use you will need an automatic tuner such as an Icom AH-4
located near the base of the pole. If the pole is mounted on a wall of the
house the tuner can be located indoors in the dry.

( My AH-4 is mounted on the inside wall of the kitchen under the kitchen
sink. It is also conveniently near to the main incoming water pipe which
serves as my best of 7 short radials. The earthing loss resistance is only 6
ohms.)

The AH-4 ( no electric motors - a set of relays) easily tunes a 32-feet
unloaded vertical wire down to the 160 meter band. It is primarily intended
for use in vehicles.

You don't HAVE to have an automatic tuner at the base of the antenna. You
can use a home brew L and C matching network on an indoors window ledge by
extending the vertical antenna wire sideways, above ground level, through
the side of a downstairs window frame. The wire is then X feet longer.

There are a number of workable variations on the tune.

If you like amusing yourself with numbers, download in a few seconds program
ENDFEED from website below and run immediately.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........


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Old February 4th 05, 08:23 PM
Dave Platt
 
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Your dry, painted timber flag-pole, with a plastic insulated antenna wire
running down it, can be located alongside a wall of your house or at the
end, side or middle of the garden.


One common house-building style around here (California) uses a
building frame of 2-by-4 or 2-by-6 wood, with an outer layer
consisting of stucco which incorporates a galvanized-steel "chicken
wire" mesh.

I'd encourage keeping HF vertical antennas well clear of any walls
made in this fashion.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
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Old February 4th 05, 09:05 PM
Photoman
 
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I have had to deal with the same situation and I found that ground moisture
plays a big part in making the ground radials work, no matter the length. I
picked up a couple 50 pound bags of rock salt, sprinkled it in and around
the radials before covering them up and it worked like a charm. Don't be
stingy with the salt... and it didn't even kill the grass. The longer the
rock salt stays in the ground the better the antenna worked. A good watering
down of the area is enough to start the process. If you live in a dry
climate an occasional watering also helps. Sure the salt will corrode the
wire but before that happened I'll probably be an SK.

That's my 2 cents worth but it worked for me. I've got up inverted Vees at
one home now and can really appreciate the real estate. I'm on the east
coast (VA) and have worked VK & ZL with 100 watts on SSB 75 and 40 meters.

73,
Ken

"jimbo" wrote in message
ups.com...
Well, I found a reference to a 10-40 meter flagpole antenna for HOAs
that don't like antennas. But they all require radials as long as the
vertical height of the antenna, and my minuscule lot just won't be
large enough for radials of any significant size. Is there any other
option for a vertical antenna for 10-40 meters that doesn't require
radials?

In another location, I used a random length dipole under the eves of
the house with a Johnson Matchbox tuner with good results. And maybe, I
can do the same with a random length dipole in the attic, but the
flagpole is an intriguing option. And I was always concerned about the
radiation in the house from the antenna and from the ladder line lead.
In fact, the irrigation solenoid valves used to open when I
transmitted.

jimbo



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