Impedance50 Ohms
ConnectorUHF socket (SO-239), N type socket on request
Gain max. 5-6 dBi in free space (3-4 dB over dipole)
F/B ratiopeak >20 dB (varies by band)
SWR<2 over the entire band (20/17/15/12/6m), 10m band: 28-29.3 MHz
Rated power1500 watt
Elementshigh strength and flexible tinned stranded copper wire 1.0 mm² (AWG 18), black PVC insulation
Spreadersflexible and sturdy fiberglass rods, UV resistant, 10 mm (~0.4") diameter
Support cords1.5 mm Dyneema® rope, UV resistant
Center posthigh quality aluminium tubing 30 x 2 mm (~1.2" x 0.08")
Mounting hardwareall stainless steel A2
Other plastic partsinjection molded from PBT (polybutylenterephthalate) black, high impact, UV resistant
Turn radiusapprox. 3.20 m (10.6 ft.)
Weightapprox. 6 kg (13 lbs)
Wind load areaapprox. 0.25 m² (2.7 sqft.)
Size when collapsedapprox. 1.15 m (45") x 15 cm (6") x 15 cm (6")
Antenna fixturefiberglass rod 5" x 1" O.D., e.g. fits into telescope masts with top section of 26 mm (1") I.D.

A cheap TV rotator can be used to turn the beam due to the symmetric structure, and the low center of gravity, low weight and wind load.

SWR plots

taken with calibrated Telepost Inc. LP-100 SWR & Watt meter, TRX Icom IC-7000, feed cable 20 meters RG-58U.
SWR at antenna feedpoint is somewhat higher due to cable losses.

swr 20 swr 17 swr 15 swr 12 swr 10 swr 6

Radiation plots

The plots for azimuth and elevation, as well as angular attenuation can be found here:

Homepage of Fritz DM2BLE