It has been well over a year since I began planning the new doublet. Usually, wire antennas don't take this long to install, but my timeline was complex because the trees here are very tall. At one end is a 200-foot pine, at the other is the "little" pine (only 100-feet tall). I spent a full year grappling with the logistics of installation, and tried almost everything along the way.
Bob, K1YO had come to install a previous antenna with his air cannon and it worked well. Unfortunately, with Covid-19 restrictions, he was unavailable and it wouldn't have been smart anyway.
A non-ham friend loaned me his air cannon, which did not work as well as Bob's. We failed to get the line appreciably high in even the "little" pine. But we spent several months trying.
I investigated using a payload drone to drop a line over the tree, but found this was not only expensive, but probably impossible due to the proximity of my QTH to an airport.
Finally, it dawned on me to hire someone to climb the trees and install pulleys. I hired a tree climber familiar with cutting trees of this type, unfortunately he didn't have the proper equipment to climb a very branchy pine without limbing as he went (although he gave it a good try). He did, however, have a recommendation for another tree guy who could do the job.
Yesterday, tree guy #2 arrived to install both pulleys and he made very short work of it. He used an ascender to get to about 90 feet, then spiked the remaining way. He went as far as he could before the trunk became too thin, by our estimate (based on the climbing rope) at about 150'. The other end made it to the top of the "little" pine, at least 90 feet. He even routed the rope from the pulleys properly so that the rope runs relatively free down from each pulley.
The idea is that the feedline can be shorted together and fed against the existing 2-acre radial field (installed two summers ago) to create a 1/4-wave vertical on 160 meters. This is accomplished with a 12V DPDT relay where the antenna comes down to the ground. I will complete work on this step shortly, but the design looks like:
This goes along well with some other station improvements, namely:
- MFJ-998 autotuner (to be permanently attached to the doublet)
- Double monitors and new wired shack network
I'll give everything a workout in Field Day this weekend, then I'll be an activator for K2H in the 13 Colonies Event. Hopefully, I'll be ready for contest season for the first time in quite a few years.