Not if the currents are balanced.

"Michael" wrote in message
...
"JDer8745" wrote in message
...
Howdy, Toy

Best all around antenna is a center fed doublet fed with balanced TL
such
as
transmitting twin lead, ladder line, or open wire line.


Dont forget a balanced feedline radiates along the line. You may have to
deal with this somehow with the Australian Communications Authority's new
radiation guidelines.

I actually meant to say induced currents not radiated since this is near
field.

Given that the ACA's radiation guidlines talks about near fields and not far
fields its probably appropriate to consider induced currents from open wire
feeders to nearby people.

As most transceivers have an unbalanced output its just as easy to make it
unbalanced at the antenna end of the transmission line anyway unless you
want to use the transmission line as part of the antenna / impedance match.
Then you can be reasonably sure there will be no radiation induced into
humans near your transmission line and be in compliance with the ACA
regulations (and safer for others I guess).



"Cecil Moore" wrote in message
...
Michael wrote:
Dont forget a balanced feedline radiates along the line.

If the currents are balanced, most of the photons are
re-absorbed by the free electrons. OTOH, if the currents
inside a coax feedline are not balanced, an unbalanced
feedline radiates along the line.
--
73, Cecil http://www.qsl.net/w5dxp



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"Michael" wrote in message
...
I actually meant to say induced currents not radiated since this is near
field.

Given that the ACA's radiation guidlines talks about near fields and not
far
fields its probably appropriate to consider induced currents from open
wire
feeders to nearby people.

From memory it specifies maximum volts/area to the distance where person can
gain access to the antenna.

It also mentions a maximum flux/area or it could be a certain induced
current in some standard measurement device I think. I haven't looked at it
for over a year now. It all doesn't matter too much when youre using coax
anyway so then you can use the standard tables they give you.

Howdy,

If the currents in the two conductors are equal in amplitude and 180 degrees
out of phase, there would be no significant rf field if you are a few
interconductor distances away from the line.

73 de Jack, K9CUN

The wires are oriented 180 degrees 'out of phase', so they will then add.
Steve k'9'd'c'i


"JDer8745" wrote in message
...
Howdy,

If the currents in the two conductors are equal in amplitude and 180
degrees
out of phase, there would be no significant rf field if you are a few
interconductor distances away from the line.

73 de Jack, K9CUN

In article ,
says...
Hi there ladies and gents. I have a question that has most likely come up
here before, and I do apologise if this is visiting old ground.

I am a novice limited license holder in Australia and pretty soon I will
have access to the 10-15 and 80M bands. I would like to know what you
consider as being the best all round antenna for my purpose? I have plenty
of room to mount an 80M dipole antenna, although height is a problem. I can
go up no more than about 50 feet.

I also have a mast and rotator, so a 0-80 triband yagi is also on the cards.

Just looking for decent ideas here guy's. I know the question is fairly
open ended, but I would like to consider all my options from those who have
all the best knowledge of what works and what doesn't. To wire or not to
wire? To beam or not to beam? To G5RV??????

I am running a TS-850, an MFJ 989C Tuner running 100W out of the box.

Thanks very much for your time and I really appreciate your response to my
questions.

Warmest regards

73 de VK2HXY
Troy

Troy -- I would suggest a G5RV antenna for starters. It'll give you the
whole spectrum from 10m to 80m. If you want to go with a beam as well
for 10/15/20, that would be a good idea as well. In my particular case,
I'm using a "shorty" G5RV which covers from 10m to 40m (about 1/2 the
size of a regular G5RV) and it does a great job, especially when you
consider I'm using an FT-817 and only putting five watts max into the
antenna!

--

-- //Steve//

Steve Silverwood, KB6OJS
Fountain Valley, CA
Email:
Web: http://home.earthlink.net/~kb6ojs_steve