In article 9,
Conan Ford wrote:

"MC" wrote in
t:

I've just replaced my old cable with some nice shiney new 50ohm coax
attached directly to my 100+ feet of longwire. As I still want to suck
that little extra out of my antenna, I want to add a balun but I am
confused with this transformer ratio stuff. I realise that a long
wire has quite a high impedance. However, should I go for a 1:4 or a
1:10 ratio balun. If I went for the 1:10 would it be overkill and
will it make any difference over the RF if I only had a 1:4. I ask
because I can get a 1:10 a lot cheaper than a 1:4.

Confused? I am

MC




1:9 is ideal for a longwire (ideal impedence is 450 ohms, matched to 50 ohm
coax, so 50:450 = 1:9), so go for the 1:10. The 1:4 is for something with
lower impedence than a longwire.

Not all baluns are created equal, however. What frequencies are they rated
for? This will depend on the turns count of the windings and also on the
ferrite material.

The impedance of the wire depends on the height above ground. The 1:9 is
most likely best.

--
Telamon
Ventura, California