Spring Antenna Repairs

May 3, 2014 - The past winter was a tough one here in Washington, DC. We had an unusually long season with significant snow, ice and the damned infamous "polar vortex." Unfortunately, my primary station encountered problems that's left me QRT since January, 2014. These issues require some technical TLC. So here's what's happening...


To get things rolling, I'm starting with external items -- antenna, transmission line and grounding / lightning protection concerns -- while the weather's still comfy. Let's face it, the weather will quickly become hot and muggy here. I'd like to tackle the interior shack issues when the summer heat moves in next month!


1) Repair KIO HEX Beam:Hands down, this antenna has been a solid performer for my primary station during the past four years. The beam is suspended as an "inverted HEX" using a pulley system draped over a branch approximately 45' high in the back yard. It's turned using the "Armstrong Method." Unfortunately, it seems the harsh winter may have tipped the scale on the performance of this antenna. I've used an antenna analyzer and determined the SWR is too high on the bands for which it is designed to operate. And a continuity test with a Multimeter revealed the center core has a "short." There's clearly a problem, so I contacted Leo, the manufacturer. After discussing the issue, I decided to replace the center core with an updated version that's distributed with newer beams. I also plan to update any insulated "P Clamps" that secure the wires on the fiberglass spacers, if any need attention.

2) Replace Coax with 400MAX Low-Loss 50-ohm Coax:After more than five years, it seems like it's time to replace all transmission lines at my primary station with new runs of low loss cable. This includes new coax for the KIO HEX (six bands, including 20, 17, 15, 12, 10 and 6 Meters), End Fed Wire (40 Meters), Cage Dipole (75/80 Meters) and an Arrow J-Pole (U/VHF). The coax should be here next weekend and I hope the weather is pleasant for some work outdoors. I'll connect each "coax run" into a dummy load and then perform antenna analyzer and a Multimeter tests to confirm each cable is functional. Lessons have been learned to complete this task before installation.

3) Add a Ferrite Bead Choke Balun:Six clip-on ferrite beads will be attached to the new coax feeding the KIO HEX. I hope to create a "choke Balun," as recommended by the manufacturer, to prevent common mode RF currents (flowing on the outside of the coax). This scenario could make the feedline act like another antenna and really screw things up. Leo's website recommends placing six ferrite clip-on beads to create a Balun at the antenna input on the center post (strapped to the center post with cable ties). I've ordered the recommended beads and plan to install the updates next weekend.

4) Replace Patch Panel Cables:I'm also adding new coax patches cables from my transceiver to the universal station ground. I've rummaged through my supply boxes and located an ICE 300U Lightning Arrestor that will be added to my 40 Meter antenna, making all of my HF antenna systems safeguarded with lightning arrestors. I hope to track down another one for my U/VHF installation that can be added later this year.