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).
EZNRC antenna diagram
EZNRC antenna diagram XY
The far field plots EZNEC gives me look like this
80m
EZNEC far field plot 80m
40m
EZNEC far field plot 40m
20m
EZNEC far field plot 20m
10m
EZNEC far field plot 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).
Thanks to help from Dave/KF4FFO and Tom/AJ4UQ, the antenna is now hoisted up into the trees and plugged into the radio. I didn’t get a chance to grab my camera, but Tom had his to take pictures with.
Antenna raised
My Hyperdog ball launcher and 4 fishing weights with some lightweight line that Dave brought proved to be a very effective combination for getting rope and antenna up into the tree.
The arms of the antenna are arranged in kind of a tilted/rotated inverted L, with one side angled down and secured to shrubs at one corner of the house, and the other side nearly horizontal. Perhaps not an ideal configuration for this. Right now everything is secured with temporary knots. I’ll spend some more time making some adjustments to the antenna before securing everything down properly.
SWR tested with Dave’s Youkits analyzer showed pretty decent SWR and impedance at 20m and 40m (~1.7 or so), so-so at 80m, maybe usable at 15m and 30m with some tweaking and not so good at 10m. Since the antenna should be able to do 10m, there’s probably some adjustment that needs to be done with how things are arranged. I think I’m going to have to get myself one of those Youkits analyzers. They’re pretty slick.
Analyzing the antenna
Radio receives pretty well on 20m and 40m so far. I can hear the WWV time signal at 5 MHz and 10 MHz pretty clearly. Heard lots of CW and digital signals on 20m after connecting up the antenna. Need to test how well I can get out next.
Right now the coax feed line just runs along the ground, but I think I’ll look into routing it through the crawl space so that it’s not lying out in the elements and won’t get run over by the lawn mower.
Now an interesting exercise will be to figure out how to use something like EZNEC and try to model what the antenna is doing.
This is a very temporary set up of our two radios, a 2m Kenwood and the HF rig.
Temporary shack setup
Until I make myself a better antenna, the 2m rig is running at 5W feeding one of my extra HT antennas (a Diamond SRH 77CA). Perhaps not ideal, but it works well enough to pick up the CARSrepeater on the Yorktown (146.790 MHz). The radio has a few issues with the display operating intermittently or just displaying random LCD segments. It receives, I just may not know what frequency I’m receiving on. Hopefully it’s nothing more than just a loose connector to the control panel.
Soon the radios will move into their permanent corner of the office/shack. Then we’ll be cooking with fire!
The gadget panel is back on the desk with the components rearranged slightly to make things work better for the desk’s new location.
Ended up having to take the power squid off the panel because the cord wasn’t long enough to reach the wall, so now everything is plugged into the UPS. Except for the computer and monitors, I think most everything else is a relatively low current load so I don’t think I’ll be overloading the UPS (I hope).
Now to clean up the space where the shack will go and start preparing to set up the radio.
