Club Member Richard VK6PZT describes how he built and tested his new 20m End Fed Vertical.
After watching a youtube video by VK2PRC I decided to have a crack at converting my 40m quarter wave ground plane antenna into a 20m Half wave end (HWEF) vertical antenna.
The 40m ground plane antenna was intended for use when portable or occasional weekend use at my QTH. It requires a 10m Squid pole, 1:1 current balun and wire for the radiating element and radials.
The main issue I was having with the ground plane antenna was the radials. The number of radials and length of the radials affected the performance and tuning of the antenna. The more radials the better and tuned radials worked better than shorter ones.
The antenna worked best with radials supported off the ground. Unfortunately the radials created a trip hazard and required too much time to set up.
The HWEF 20m vertical dipole could be used with one much shorter counterpoise or using the shield of the coax feed line as the counterpoise. The vertical dipole also has the advantage of a lower radiation angle than the quarter wave. So it seemed like a good option, and VK2PRC says it works great.
The build was straight forward. It only required the construction of a matching unit using a T200-2 Toroid, enamelled copper wire, some coax for a high voltage capacitor and a few connectors.
The instructions provided by Alex (VK2PRC) were easy to follow, and his advice on how to tune the matching unit using a 3k ohm resistor proved to be sound.
I suspect my toroid (found in a junk box) wasn’t a T200-2 as recommended but it tuned up fine, and as a result the coaxial capacitor was short enough to fit inside the project box (bonus).
As suggested by Alex, I erected the squid pole using some poly pipe strapped to a fence pole in my front garden, with the matching unit mounted at head height. The poly pipe doubles as a protective case for the squid pole while not in use. The radiating element was trimmed to around 9.8m ish to obtain an almost 1:1 SWR.
And hey presto … the antenna worked a treat.
I fired up WSJT-X and immediately obtained more F8 DX contacts than I’d ever achieved in all my previous efforts!
I also gave WSPR a go, having never used it previously. Not being familiar with the WSPR mode, I thought my luck had run out, as I could not see the results within WSJT-X ….. turned out I was wrong. The following morning, I received an email from Brian VK6TGQ complimenting me on how successful I had been on WSPR! The screen shot he sent to me is included below.
For my next project, I intend to build a heavy-duty matching unit or buy one from VK2PRC for use at 100w SSB or CW on a more permanent installation of the same antenna.
I need to send a big Thanks to Alex VK2PRC for a great job with his you tube video.
Page Last Updated : 3rd May 2021 by VK6TGQ