The 2 Element Diamond HB9CV Yagi-uda 50MHz antenna had been assembled for two weeks but had be sitting on the roof awaiting to be installed because the waether had been bad. Finally with the assistance of Charlie, VR2XMT we had a chance to install it on the afternoon of the 26th April, 2008 (Saturday) as there was a spell of good weather.
Below is a photograph of the erected antenna shortly after installation on my roof.
After installation a comparrison was made with a 50MHz vertical and it was immediately apparent that the noise was much less on the horizontally polarized Yagi-uda making it more suitable for long range DXing, a Philips light weight programmable azimuth rotator is used for steering beam in directions require. The control box is digital with it's own infra red remote control and can store uop to 12 memories for beam headings.
Below in a simple beam heading azimuth chart that was run on the computer. The center is Hong Kong and this is a Great Circle beaming heading map. For example Europe is 330 degrees.
Below are the specifications for the HB9CV antenna which is also RoHS compliant:
50MHz(6m)2-ELEMENTS PHASED DRIVE BEAM ANTENNA
A502HBRFrequency:50 to 53MHz(Center frequency without adjustment is set to 51MHz)
VSWR: Less than 1.5:1(50 to 52MHz without adjustment)\
FB ratio : More than 15dBHalf power band width: Less than 70degrees
Wind surface area:0.14m2 Rated wind velocity:40m/sec.
Turning radius: approx.1600mm
Connector:M(M-J) Mast diameter accepted:25mm
Dimensions:800mm x 3000mm x 85mm