On Sun, 26 Jun 2005 23:56:09 -0400, "Hal Rosser"
wrote:


"Dan Richardson arrl net" k6mheatdot wrote in message
.. .
In your original post you said:

"The only thing I have against them (current baluns) is
They are heavy.
and cause the antenna to droop lowering the height of the feedpoint."

Anyway, with say fifty pounds of tension just how much drop are you
talking about? And what difference does it make?


Apparently it makes more difference to me than it does to you.
I don't want it digging into the tree branches.
Nothing wrong with your view - its probably a better-informed view than
mine - but I'll still use balanced line and I still think baluns are too
heavy. I'm just hard-headed that way. :-)


You may choose to use the balun near the ground where its weight can
be supported and you can use coax to bring in the lead from outside.
The piece of balanced line will give you low loss to the balun and the
loss from the coax will be minimum due to the short length.

--
73 for now
Buck
N4PGW

On Mon, 27 Jun 2005 03:41:01 GMT, "Chris Trask"
wrote:

I came across a very
interesting 1:1 design that uses two equal length pieces of coax that would
each be less than an eighth of a wavelength long and which has a very wide
bandwidth. I copied the schematic (which has a slight error) and the photo
to a single sheet PDF file if anyone's interested.

I would be interested. I can leave an address or you can get it from
QRZ.

thanks


--
73 for now
Buck
N4PGW

Apparently it makes more difference to me than it does to you.
I don't want it digging into the tree branches.

That's a fair point. The sag in a dipole supported only at the ends is
very sensitive to the suspended weight in the middle. And if the end
supports are trees, the problem can become extreme.
*******************
Yes, I use trees whenever possible - and install the antenna with a
bow-and-arrow
************************


Nothing wrong with your view - its probably a better-informed view than
mine - but I'll still use balanced line and I still think baluns are too
heavy. I'm just hard-headed that way. :-)

If sag is a problem, don't use 300 or 450-ohm ladder line. In terms of
weight and windage, it is a very bad solution. A much more practical
solution is to make your own ultra-lightweight parallel line. The wire
can be much thinner than the main antenna, and you can use a spacing of
several inches with the absolute minimum number of ultra-lightweight
spreaders.
*******************************
Usually 300-ohm twin lead is light enough
***************************


But more important than that, please stop calling it "balanced line".
Somehow we have got into the habit of kidding ourselves that
parallel-wire line is balanced line. It isn't!
*****************************
When I use a balun to feed it - then its balanced line - and that's what I
was talking about.
But I see your point
Henceforth I dub it "twinlead"
*******************************

Parallel line does NOT automatically balance itself. It will cheerfully
allow unequal currents on the two wires. That's the same as saying it
will cheerfully support an unwanted common-mode current (same magnitude
and same direction on both wires) in addition to the wanted
equal-and-opposite currents.

So parallel line will NOT be balanced line - not until you have done
something to MAKE it balanced.
************
(Like using a BalUn ??
*********************


Thanks for your input