How does one check the balance between two parallel feed wires into a
doublet antenna. Neon bulbs or some sort of meter gizmo?

tnx

d

That topic was discussed in some detail on this newsgroup just a few
weeks ago. Do a search in groups.google.com of this newsgroup for the
topic "unbalance indicator".

Roy Lewallen, W7EL

Big Endian wrote:
How does one check the balance between two parallel feed wires into a
doublet antenna. Neon bulbs or some sort of meter gizmo?

tnx

d

How does one check the balance between two parallel feed wires into
a
doublet antenna.

===========================================

Just go out into the garden and look up at the antenna.

If each half of the doublet is of about the same length, and both
halves are about the same height above ground, then the parallel pair
of wires are balanced.
----
Reg.

Reg Edwards wrote:
How does one check the balance between two parallel feed wires into
a
doublet antenna.

===========================================

Just go out into the garden and look up at the antenna.

If each half of the doublet is of about the same length, and both
halves are about the same height above ground, then the parallel pair
of wires are balanced.

In your opinion.

But the original questioner wants to measure what's *really* happening.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

"Ian White wrote
But the original questioner wants to measure what's *really*
happening.
========================================

But the original questioner can tell what's *really* happening just by
inspecting the antenna and feedline. He doesn't need any electrical
measuring instruments.

Of course, it may be in the middle of the night, in which case it
would be best to wait till the sun comes up.

Or he could rely on his memory of how he installed the antenna.

The trouble with you experts is that you overcomplicate matters and
make quite simple, obvious things appear to be mysterious.

But you have to justify your existence in one way or another. smiley
----
Reg.

In article ,
"Reg Edwards" wrote:

"Ian White wrote
But the original questioner wants to measure what's *really*
happening.
========================================

But the original questioner can tell what's *really* happening just by
inspecting the antenna and feedline. He doesn't need any electrical
measuring instruments.

Of course, it may be in the middle of the night, in which case it
would be best to wait till the sun comes up.

Or he could rely on his memory of how he installed the antenna.

The trouble with you experts is that you overcomplicate matters and
make quite simple, obvious things appear to be mysterious.

But you have to justify your existence in one way or another. smiley
----
Reg.

Actually I want to monitor the antenna because I have a splice in the
feedline and the feedpoint is subject to wx, snow ice and rain. Some
times the feedline itself is covered with snow and ice. I would find it
interesting to see what is happening when I see my SWR shoot up and
retuning my matchbox. I also have a strange thing happen when I apply
high power, I get a slight bump up in SWR suddenly. I often wonder if
one of my end insulators are breaking down under 1KW of RF or if there
is some imbalance on one leg due to ground or trees swaying in the wind.

On Sat, 25 Feb 2006 18:18:35 GMT, Big Endian
wrote:
"Ian White wrote
But the original questioner wants to measure what's *really*
happening.
========================================
But the original questioner can tell what's *really* happening just by
inspecting the antenna and feedline. He doesn't need any electrical
measuring instruments.

Actually I want to monitor the antenna because I have a splice in the
feedline and the feedpoint is subject to wx, snow ice and rain. Some
times the feedline itself is covered with snow and ice. I would find it
interesting to see what is happening when I see my SWR shoot up and
retuning my matchbox. I also have a strange thing happen when I apply
high power, I get a slight bump up in SWR suddenly. I often wonder if
one of my end insulators are breaking down under 1KW of RF or if there
is some imbalance on one leg due to ground or trees swaying in the wind.

Hi OM,

Reggie is particularly obtuse to this matter. Simple observation of a
dipole that is symmetrical to earth does not guarantee balance. When
that twin lead arrives at your gear, you can easily wipe that out (the
presumed balance) through an inappropriate connection to ground
(through any number of paths that are commonly overlooked in the
shack).

Snow and ice on the line are not likely to impart a common mode
current, but as revealed by bench test by contributors here, the
characteristic Z of the line can change drastically, which then upsets
the tune, where it follows SWR begins to change - noticeably. If your
feedline is coaxial, then the ice is of no consequence, but that does
not remove the jeopardy of common mode current. There you need to
look at how you isolate the line from the drivepoint.

73's
Richard Clark, KB7QHC

"Big Endian" wrote
Actually I want to monitor the antenna because I have a splice in
the
feedline and the feedpoint is subject to wx, snow ice and rain.
Some
times the feedline itself is covered with snow and ice. I would
find it
interesting to see what is happening when I see my SWR shoot up and
retuning my matchbox. I also have a strange thing happen when I
apply
high power, I get a slight bump up in SWR suddenly. I often wonder
if
one of my end insulators are breaking down under 1KW of RF or if
there
is some imbalance on one leg due to ground or trees swaying in the
wind.

=======================================

Perhaps you should have mentioned all this in your original enquiry.
The people you expect replies from are not mind readers!
----
Reg.

Reg Edwards wrote:
. . .
The trouble with you experts is that you overcomplicate matters and
make quite simple, obvious things appear to be mysterious.
. . .

I recently finished reading Richard Hofstadter's _Anti-Intellectualism
in American Life_ (written in 1962, won a Pulitzer prize in 1964), where
the author shows in great detail that a general disdain for education,
sophistication, and complexity is a very deeply seated American
tradition. That general outlook was virtually a basis of the founding of
a number of now-mainstream religions, and has had lasting impacts on our
educational and political systems. In short, it's a long and dearly held
American tradition.

So, Reg, that was a very American thing to say. You'd fit right in here.

Roy Lewallen, W7EL

Reg Edwards wrote:
If each half of the doublet is of about the same length, and both
halves are about the same height above ground, then the parallel pair
of wires are balanced.

What if one is broken and you don't know it?
--
73, Cecil http://www.qsl.net/w5dxp