RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Antenna (https://www.radiobanter.com/antenna/)
-   -   Loop Question (https://www.radiobanter.com/antenna/2419-loop-question.html)

Theplanters95 October 8th 04 07:00 AM

Correction! That's 4 masts of f foot length.

Randy

Richard Clark October 8th 04 05:08 PM

On 08 Oct 2004 06:00:32 GMT, ospam
(Theplanters95) wrote:
Correction! That's 4 masts of f foot length.


Oh! Well, then - nevermind ;-)

Theplanters95 October 8th 04 10:48 PM

I cannot type. I have an offer of 4 pipes of 5ft length. Would placing them
on the eaves help?

Randy

Richard Clark October 8th 04 11:14 PM

On 08 Oct 2004 21:48:22 GMT, ospam
(Theplanters95) wrote:

I cannot type. I have an offer of 4 pipes of 5ft length. Would placing them
on the eaves help?



Hi Randy,

You mean one at each corner or the house for 5 foot elevation? Or do
you mean all four combined for a one time gain of 20 foot elevation?

I have an Army field grade mast kit with 8 five foot heavy duty pipes
that does a good job (the kit also includes stakes, cording and plates
for 3 tiers of guys, and a 2.5 pound sledge). Works fine, but if I
wanted 20 feet, I would go buy two 10 footers. You have to be careful
these days about your pipe sources. Some in the CIA would claim they
could be used in Uranium Centrifuges and a cruise missile may be
targeting you soon.

If we fall back on the 4 spread among the corners - nah. Too much
work for wholly no observable gain.

73's
Richard Clark, KB7QHC

Dave October 8th 04 11:14 PM

only if you want the neighbors to think you have an antenna... or some other
weird contraption on the roof!

"Theplanters95" wrote in message
...
I cannot type. I have an offer of 4 pipes of 5ft length. Would placing

them
on the eaves help?

Randy




Theplanters95 October 9th 04 07:37 AM

It would not look good for a preacher to be hit by a cruise missile. :-) Hmmm,
maybe the flaming arrows of spam are from the cia???

Ok, I will scrap the 4 pipes around the house for loop's extra elevation, and
use them for elevation for a 2m J-pole.

With the power company feedline coming in at the front (away from feed point.
would a "U" shape (that is a loop with a gap around the power line) work. I
think that I just realized the answer. It would or could cause an unbalanced
situation which could lead to all sorts of problems like RFI, unable to tune,
etc....

I am also thinking of running the loop along the backside of the house and
then instead of continuing to run along the side of the house, run the wire to
an old unused billboard (about 20 or 30 feet high) and then from the billboard
back along the front of the house, and then instead of along the side, run it
to a tree (the only one on my property) and then back along the side of the
house. The feedpoint would be on the backside about 1/4 or 1/3 from the tree
side.

An idea, if, I use the 2 of the pipes as additional supports placed at the top
of the side eaves , I could run a wire from the tree over the roof to the
billboard, sort of an inverted V or a droopy end dipole with a slight bend on
one side. And if the pipes are placed just right, then I would not be running
a wire under a power feed line, like the loop on the eaves. It would be random
length, and feed about 1/3 or so from the tree end, unless I got more
ladderline. Total length about 60 or 80 feet at about 20 or 30 foot sloping
down to about 10 or 15 feet at the tree. Let's see, a random length dipole in
the clear (by a few feet), should out perform a loop under the eaves? Easier
matching, antenna in the clear, less RFI, better for NVIS and DX. Maybe a
better antenna?

Can an OCF dipole be feed with ladderline?
What is the best way to run ladder line over asphalt shingles?

Randy


Richard Clark October 9th 04 08:28 AM

On 09 Oct 2004 06:37:43 GMT, ospam
(Theplanters95) wrote:

With the power company feedline coming in at the front (away from feed point.
would a "U" shape (that is a loop with a gap around the power line) work. I
think that I just realized the answer. It would or could cause an unbalanced
situation which could lead to all sorts of problems like RFI, unable to tune,
etc....


Hi Randy,

All of this is actually a long shot - very unlikely. If it DID happen
you have a scapegoat, but RF is not that delicate a flower rent by the
hurricane of speculation. In other words, try it to see if you have
a problem. You will spend far less trying compared to the time
worrying about the possibility.


I am also thinking of running the loop along the backside of the house and
then instead of continuing to run along the side of the house, run the wire to
an old unused billboard (about 20 or 30 feet high) and then from the billboard
back along the front of the house, and then instead of along the side, run it
to a tree (the only one on my property) and then back along the side of the
house. The feedpoint would be on the backside about 1/4 or 1/3 from the tree
side.


Now you are cooking with gas. Imagination is kicking into high gear
and invention is working with real possibilities.

An idea, if, I use the 2 of the pipes as additional supports placed at the top
of the side eaves , I could run a wire from the tree over the roof to the
billboard, sort of an inverted V or a droopy end dipole with a slight bend on
one side. And if the pipes are placed just right, then I would not be running
a wire under a power feed line, like the loop on the eaves. It would be random
length, and feed about 1/3 or so from the tree end, unless I got more
ladderline. Total length about 60 or 80 feet at about 20 or 30 foot sloping
down to about 10 or 15 feet at the tree. Let's see, a random length dipole in
the clear (by a few feet), should out perform a loop under the eaves? Easier
matching, antenna in the clear, less RFI, better for NVIS and DX. Maybe a
better antenna?


Whoops! Backsliding to that familiar nemesis of "a solution in search
of a problem." You are trying too hard to put those tubes to work -
use the abandoned sign. Dare I say it is a "sign?" The metaphor is
certainly not lost on you is it? ;-)

Can an OCF dipole be feed with ladderline?


It typically is and it typically is fed with coax too - howabout that
for political answer - sorry, watching too many debates. We taped the
soap opera when we went out to listen to Mort Sahl here in town. Mort
is getting on in age (wish I could have caught his act at the Hungry I
in Frisco) but he is as sharp as a tack still... and then we got back
for the punch and judy show as a retread. I wanted to throw the
remote at those two monkeys. Politics is a sure argument against
Darwin (evolution caught in a time warp).

OCF guarantees Common Mode for any feed. It is up to you to force a
new balance.

What is the best way to run ladder line over asphalt shingles?


The asphalt isn't a problem, it's the water and crud that comes with
the rain that bridges the wire. Use coax for short runs because you
would need standoffs (like they used to use for TV twin line back in
the old days) but you are back to loss due to water and crud that
comes with the rain that bridges the wire (get the idea?).

Or just simply ignore the loss of the water and crud that bridges the
wire (or ignore the loss of coax) and get on with the fact that no one
can tell the difference with WHAT you use (come what may, rain OR
shine).

One of the supreme ironies is that most folks achieve their greatest
improvements with very little work, and then they have to struggle to
double that performance gain - and then they have to quadruple that
heroic effort to double it again. Ever hear about the problems of
Sisyphus?

73's
Richard Clark, KB7QHC

Theplanters95 October 9th 04 09:45 AM

Ever hear about the problems of
Sisyphus?


No, Can't say that I have heard of that.

The tubes was thinking out loud. I would like the wire to clear the roof, and
I cannot remember if that tree is tall enough. I also cannot remember if the
sign is tall enough -- it is a non standard billboard.

Randy

Dave October 9th 04 12:19 PM


"Theplanters95" wrote in message
...
Ever hear about the problems of
Sisyphus?


No, Can't say that I have heard of that.

The tubes was thinking out loud. I would like the wire to clear the roof,

and
I cannot remember if that tree is tall enough. I also cannot remember if

the
sign is tall enough -- it is a non standard billboard.

you know what... it doesn't matter. pick one, put up some wire, and put the
rf to it. situations like this are WAY too complicated for even the most
dedicated computer modeler. the best recommendation anyone can make in
cases like this is "Plug it in and try it". if it works, great, if it
doesn't work or causes problems then change something and try again.




All times are GMT +1. The time now is 06:43 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com