[Elecraft] 4:1 balun

[Augie "Gus" Hansen]

On 12/10/2011 2:35 PM, Jim Dunstan wrote:
> ... I don't know if anyone uses it for making folded dipoles (I 
> suspect not). If one were to construct such a folded dipole for 
> any HF band I can guarantee they will not have any power handling 
> problems to today's legal power limit.

In this weekend's ARRL 10m contest, one of the antennas I'm using is 
a vertical folded dipole fashioned from transmitting quality 300 Ohm 
window line and matched at the TX end via a 4:1 balun. I'm running 
only 100 watts for this contest, but it can handle full legal limit 
with ease.

This antenna system provides a minimum VSWR of about 1.4:1 at 
resonance (28.5 MHz) due to the slight mismatch (75 vs 50 Ohms) and 
less than 1.7:1 at the 10 meter band band edges.

73,
Gus Hansen
KB0YH