Ultrabeam - Blog - PA7MU

NEW Ultrabeam 4 elements yagi 6-20 meters DX

Frequency range : 14 - 50 Mhz

4 elements yagi :10-12-15 meters
3 elements yagi :17-20 meters
Gain 10-12-15 meters (dBd / dBi) : 8 / 10,15
Gain 17-20 meters (dBd / dBi) : 6 / 8,15
F/B ratio (dB) : 25
Power (PeP) : 3500 watt
Longest elements : 11 meter
Boom length : 6,3 meter
Boom diameter : Square 60x60 mm.
Max wind-area : 0,75
Rotating radius : 6,25 meters
Mast diameter : 50mm (60mm possibility)
Weight : 35 Kg. Controller : Included.               current price 1990 Euro

Balun 2:1

All Ultrabeam yagis work with an impedance of approximately 25 Ohms.

For this reason, driven-element motor-units use a 2:1 Balun to transform the 50 Ohm impedance of the feeding-line (coaxial cable) to 25 Ohm to be presented at the feeding-point. For the construction of a very reliable Balun, Ultrabeam hs adopted one of the many projects made by the famous Jerry Sevick (W2FMI) who was and still is, a world-wide reference in the field of transmission-line impedance transformation .The schematic of the Balun requires a special coaxial cable with an impedance of 25 ohm, adequate section and insulation. This is the reason why we do not use commercial coax cable and wrap it by hand in our laboratories. See WEBSITE