Until recently most of my ham radio activity has been QRP/remote. I have not had an antenna continually installed at my house and have not taken the time to setup a proper ground system. Until recently most of my ham radio activity has been QRP/remote. I have not had an antenna continually installed at my house and have not taken the time to setup a proper ground system. I recently installed an end-fed wire antenna running from the apex of my garage into a large maple tree in my backyard. I want to get the best performance I can from the antenna and also take the appropriate precautions to operate safely and protect my equipment.
There is a lot of information about how to setup a grounding system for radio. Here is a summary of some of the key points I've learned about setting up a ground system:
- Use a single-point ground inside of the home. A sheet of copper (0.5mm thick) screwed into a wooden board will work well for this.
- Electrically bond all "earthed" items outside of the home together using mechanical attachment methods. This system should be bonded to ground rods driven into the ground.
- Use Lightning arrestors on each coax line to shunt high voltages to ground
- 1ft x 1ft 0.5mm thick copper sheet (for internal "single point" ground)
- 1/8" thick copper sheet – approx 2in x 8in. This was leftover from the loop antenna project.
- Copper braizing rod and torch
- Utility enclosure kit: https://www.dxengineering.com/parts/DXE-UE-2P
- Lightning arrestors: https://www.dxengineering.com/parts/ALF-ATT3G50UBHP. *** See note below!
- Solid-core 6 AWG copper wire from Home Depot
Note: these lightning arrestors are chassis-mount meaning they are grounding through the PL-259 connector and they do not have a threaded hole on the body of the arrestor. You can save some effort by purchasing an alternate arrestor with the threaded hole that can be directly connected to a metal plate with a bolt.
Since my arrestors are chassis-mount I want to connect them to ground plane with a minimal amount of resistance and plenty of current-carrying capacity. I'm using some leftover copper from the loop antenna brackets I recently worked on.
First, cutting a couple of small strips of copper. I used a band saw for this:
I then cut holes into them and added a bend using a vice and hammer:
I drilled some holes and used M3 bolts to hold these brackets onto a 2" wide 1/8" thick sheet of copper ground plane. These bolts helped hold the copper securely as I brazed them into place:
This was my first attempt brazing copper. It took two tries. The first time failed because I didn't get the material hot enough. I had what looked like a "cold solder" joint where the brazing material bonded to the brackets, but didn't adhere to the larger copper sheet. The 2nd time worked great. I found I needed to heat the copper for 4-5 minutes before the brazing rod would flow and wick correctly into all of the pieces. The copper was nearly red hot by the time I started brazing.
Close up of the connection after some cleanup with a wire brush:
Arrestors installed onto bracket after some additional cleanup:
And the whole setup installed in the utility box on the side of the house near my workbench and the electrical panel for the home:
Inside of the house, I have a single point ground installed with my coax selector switches mounted to it:
- Use a 2in strip of copper to connect the interior station ground to the exterior ground. This will have lower inductance and will provide better RF grounding.
- Measure the ground resistance and consider adding additional ground rods.
- Install a 2nd antenna (planned to be a 2m/70cm antenna)
- Cleanup coax routing at the ham radio bench
Its been nice having an antenna installed at home and its very convenient to not have to run coax out the back door every time I want to run a test. I don't think my end-fed installation is optimal by any stretch, but its a massive improvement over no antenna at all! It will be interesting to compare the results to my loop antenna.
A couple of nights after installing the antenna I saw a lot of activity on both 20m and 40m. Here is a portion of the 20m band that night (2022/05/18).