The KC8RKQ 2 Meter Coathanger Antenna Experiment - Part 2

Well, I wasn't totally satisfied with the antenna's performance... I thought it could be better; it turns out I was right...

A friend loaned me his MFJ antenna analyzer (Thanks Rick!) so I could check this thing out. Boy was I surprised at what I found...

The impedance was AT BEST 75 ohms where the antenna resonated. I said to myself, "What? It should be LOWER than 75 ohms, if anything!" I still haven't figured it out, but that's what the analyzer said.


So, as an experiment on my experiment, I decided to try bending the ground plane elements down about 40 degrees, to see what happened. The picture is below.

I did that, and the match went through the roof! The antenna was now too long. The funny thing was the impedance was now in the range where I wanted it, so I started trimming...


After taking an inch and a half off the wire I'd soldered on to the end of the radiating element, the match came back down. and boy howdy did it ever come back down! Here's the new figures...

 
Frequency
SWR
Impedance
144.000
1.2:1
50
146.000
1.0:1
40
148.000
1.2:1
50

I also decided to get the antenna up a few more feet. It's now roughly 11 feet off the ground, as opposed to the 4 1/2 feet or so it was. I have more pictures...
    
Two views from the southeast and the northeast. In the left picture, the window at the bottom, just past the concrete base for the rail, is my window. The antenna is almost level with the gutter above my upstairs (first floor) neighbor. I haven't heard any reports of interference yet.


A view of the antenna on the top mounting pole. The pole is sectional, so I can take it up and down easily. There's just enough coax to separate the poles and move it over to the side. The gutter there is one of the ones I'm going to load up when I get my HF privileges. (Morse Code is NOT being nice to me!)

Anyway, this antenna is done, for now, except I still need to figure out how to weatherproof it. I've got some ideas on how to do that, but that will be for part 3.


Thanks again to KC8HEZ, Rick, for the loan of his Antenna Analyzer.

73 de KC8RKQ