Imabug's journey into electronics and amateur radio as AB4UG and VA6BUG
From the street, the antenna is practically invisible against the trees, aside from the white rope used to secure one of the wires (and sometimes even that’s hard to spot).
Both ends of the antenna float, with tension provided by a couple of surplus weights
Coax goes up the house to the eaves where it meets up with the ladder feedline of the antenna
From the other side, the antenna and ropes are a little more visible against the sky
After a week of being temporarily tied to trees and bushes, I finally got around to anchoring the antenna a little more securely using some eye screws. In the process I was able to raise the center of the antenna up another couple of meters which might help things.
One arm of the antenna is weighted down with a 2lb weight and floats up and down so that it can move with the trees. The center and other leg are tied down with enough slack to handle windy days. I may change them so that they’re just weighted down as well rather than tied off.
The coax got routed through the crawl space so I won’t have to worry about running over it with the lawn mower. It runs up the side of the house through another eye screw to the antenna feed line. When the radios get moved into their permanent location in the office/shack, I’ll look at some floor or wall connections for the coax.
I thought I’d see what I got out of EZNEC for modeling the three antennas on the wifi router. I treated each of them as single wires at 2.452 GHz about 1m off the ground (not the floor). Each wire was 8 cm long (0.654 lambda) spaced 8 cm apart. Radiation pattern is directed perpendicularly to the plane containing the antennas, so I have two of them pointed down (the wifi router is mounted to the side of the desk) and one pointed off to the side (there’s a power strip that gets in the way of it pointing down like the others).
After reading through some of the original documentation for NEC learning about the somewhat arcane input format (like MCNP, it can be pretty confusing at first), I’m liking how EZNEC simplifies and hides some of the complexity, but is still accessible if needed. When I start getting into building antennas, I might have to get a copy of it.
I was able to find some EZNEC model files for a G5RV antenna including the feed line and tried to modify it to match my current antenna setup. 40m and 80m are pretty much the same, but the radiation patterns for 20m and 10m become a little more complex compared to my initial model.
10m
20m
Here’s EZNEC’s SWR plot
Using the EZNEC ARRL version that comes in the ARRL Antenna book, I attempted to create a simple model of the antenna as it’s currently set up.
Using a tape measure and some very rough estimating, I came up with this plot of how the antenna is set up, without the ladder line in the middle (haven’t figured out how to add the feed line yet).
The far field plots EZNEC gives me look like this
80m
40m
20m
10m
The antenna model is pretty simple and nowhere near perfect. I’m probably missing a lot by not having the feed line included. Based on these rough simulations though, it looks like I’m warming a lot of clouds (ham speak for when your antenna is sending radiation mostly straight up).