In article ,
David wrote:

On Sat, 27 Jan 2007 17:55:17 -0800, Telamon
wrote:

In article ,
David wrote:

On Sat, 27 Jan 2007 12:05:57 -0800, Telamon
wrote:


Snip

That would depend on the application like anything engineered. In
general the current type would be best for Hertzian antennas and I would
only use the voltage type on random/long wire Marconi type antennas.

http://www.moonraker.com.au/techni/q...everticals.htm

What does this have to do with BALUNs?

A random wire is not a Marconi antenna. A Marconi antenna is a 1/4
wave vertical with a formal ground screen/radial system providing a
second 1/4 wave image below the earth which allows the system to load
like (but radiate like) a half-wave antenna. A Marconi antenna is ca.
36 Ohms and needs no 9:1 or 10:1 transformer.

A Marconi antenna is not necessarily a quarter wave vertical but is a
quarter wave or longer.

In the beginning of the development of radio technology there came about
two main styles of antennas. A Marconi style is a one element where the
other is a ground. Hertzian's are balanced antennas with two elements in
the air.

Irrespective of antenna style 1/4 wave is a basic element.

Single element antennas can pick up static electricity that can damage
radio front ends. Using a voltage type UNUN is best type to use due to
the separate windings. The voltage type also lends itself to fractional
impedance transformations.

Balanced antennas can be of a closed RF loop design where the higher
efficiency of the current type transformer is a plus and static
electricity is not an issue.

--
Telamon
Ventura, California