A new 12.5 ohm / 50 ohm UNUN has arrived. It is built by Balun Designs LLC and is made with two cores for increased power handling = 10KW. It has a 7/16 DIN connector on the 50 ohm side.
Currently viewing the tag: "antennas"
I pulled out the top loading wires of the antenna.
A lot of work remains with the elevated radials and connections at the feed point.
Today the winds finally settled and in between freezing rainshowers I decided to hoist up the 60 pound insulators and antenna wires for the King´s antenna.
The antenna wires are #8 CopperWeld – copper covered steel wires with a breaking strength of 2500lbs / 1100kg.
My good neighbor, Finnbjörn from Litlaeyri, Airport Manager, came to assist me on the ground and he took these photos on my camera.
I began by pulling up the right hand side insulator and antenna wires while still on the ground. I then attached a climbing rope to my harness and the other end to the left hand insulator and antenna wires already assembled on the platform.
Attaching the right hand side insulator went well, but the climbing rope attached to the other insulator managed to wind itself around the feedpoint box at the bottom of the pole.
Finnbjörn came to the rescue and untangled the rope, saving me a trip to the platform and back up again.
It was extremely difficult to attach the second insulator until I discovered that one of the antenna wires had snagged on the platform. Finnbjörn also saved me a trip back down by untangling the wire.
This was the most difficult part of constructing this antenna and I am glad it is behind me. I must be getting old 
I have finished the task of installing the omni-directional antenna.
It is installed approximately 250 meters from the shack, and it is fed with 1-5/8″ Heliax.
It measures with relatively flat SWR from 3-30MHz.
It remains to be seen whether it is installed too close to some of the Beverage antennas, and whether the presence of the vertical will have any detrimental effect on the directivity of the Beverage antennas.
The structure is 60 feet tall and occupies a space of 40 meters in diameter (130 feet) and it was difficult to find a level area for the installation.
I have now prepared the antenna wires out of #6 CopperWeld steel wire with 60lbs insulators.
I must wait for better weather to install the antenna on the King.
I had previously ordered a line isolator or a 1:1 balun from ArraySolutions in the belief that it was the best available.
I learned that Balun Designs LLC were making a similar item with even greater isolation.
An inquiry to ArraySolutions by email asking them to provide me with test data on the isolation impedance of the choke resulted in no reply.
I am disappointed by this, I expected more from ArraySolutions.
The same question posed to Balun Designs resulted in an answer within minutes – On 160 meters the choking impedance is 1536 ohms at 1.8 MHz.
I purchased the Max choking model along with a 1:2 UNUN (25 to 50 ohms) both of which are obviously of high quality.
I have since learned that the impedance of the King´s antenna will be close to 15 ohms, so I should have ordered the 1:4 UNUN but not to worry, I will be building other antennas later and will find a use for it.
I have finished the task of guying the King and the Rooks.
A formidable amount of hardware was consumed by the project.
Soon I will be able to start construction of the antenna itself.
Building the guy wires for the King and the Rooks is difficult and time consuming. I have now spent a few days on this task.
Most of the guy wires are made of 5/16″ galvanized EHS steel cable.
I finished the guy wire installation for the King today.
photos by Finnbjörn Bjarnason of Litlaeyri.
