Surfin’: Logging Periodically
By Stan Horzepa, WA1LOU
This week, Surfin’ can begin antenna maintenance now that the trees are out of the way.
The tree man finally showed up on Monday and cleared the area around my crank-up/down tower, so I can now lower it without the antenna hitting any branches on the way down.
The antenna is a log periodic and is the actual one Bart Jahnke, KB9NM, reviewed way back in the August 1988 issue of QST. It is the Creative Design CLP5130-1 VHF/UHF log-periodic antenna and it has served me well for a couple of decades, but it needs maintenance.
From the ground 55 feet below, I can see that the coaxial cable feeding the antenna is loose and needs to be tethered to the boom of the antenna.
I am also concerned about the arrestor coil mounted on the back side of the boom. The antenna manual states: “Please take care not to bend or deformed [sic] the arrestor coil.” But over the years, that coil has suffered from handling and transporting the antenna and I am sure it no longer resembles the coil, as it was mint out-of-the-box circa 1988.
The manual provides the dimensions of the width of the coil, so I hope that will be enough to get the coil back into shape, but you never know when you fool around in the science of antenna design.
By the way, searching the Internet for antenna arrestor coil information was not very fruitful. The best search results pointed to the online PDF of my antenna’s manual!
On the other hand, if you seek general information regarding log-periodic antennas, the Internet has it. For example, Radio-Electronics.com has an overview, summary and tutorial about log periodic antennas.
Until next time, keep on surfin’!