How to Build VHF Antennas
Building antennas has long been a favorite for ham radio operators. Working on the VHF band will allow you access to the frequencies from 144.0 to 148.0 Mhz. Once you have your antenna up and running, you will be able to transmit and receive on any of these frequencies. Before you start, you will need to know how to build VHF antennas for the 2-meter band. Following a few quick steps and having the right material will make the project go easier. The good news is that most of the materials you will find around the average house, so this will help keep the expense to a minimum.
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Things You'll Need
- 5-6 metal coat hangers
- Wire cutters/strippers
- Pliers
- Utility knife
- Solder
- Soldering gun
- SO-239 connector
- 4 bolts/nuts/washers (size #6)
- Clear sealant caulk
- Sandpaper
- Measuring tape
- Antenna analyzer
- Safety glasses
Instructions
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How to Build VHF Antennas
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1
Cut the heads off of each of the coat hangers and completely straighten out each of the wires. Once straightened, sand off all of the paint and covering to expose the bare wire.
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2
Using the pliers, put a tight bend to form a circle just large enough for the bolts to fit through on four of the wire rods.
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3
Taking those same four rods, measure and cut each to exactly 21 inches. Be sure to cut the end opposite the mounting hole from the previous step.
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4
Mount each of the 21-inch cut rods to the four holes in the SO-239 connector with the bolts, nuts, and washers. Tighten them to a snug fit. Holding the SO-239 eye level, bend each rod (element) at the base of the SO-239 in a downward motion to about 45 degrees.
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5
Take an extra rod and put a small bend at the top to form a circle. This will be used to hang the antenna. Cut the rod to measure exactly 20 inches. (once inch shorter than the elements)
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6
Insert the rod into the pin of the SO-239 connector and, while holding this carefully in place, use the soldering gun to solder the rod to the pin. Be careful to not overheat the pin and melt the plastic insulation on the interior of the plug.
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7
Using the hole on the top rod, mount the element to a rafter in the attic or other suitable location.
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8
Using the antenna analyzer per the manufacturer guidelines, measure the SWR (Standing Wave Ratio). Trim each of the four elements about 1/4 inch at the same time to achieve the lowest SWR at the center of the frequencies between 144-148 Mhz.
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1
Tips & Warnings
Be sure to wear safety glasses to avoid damage to the eyes from the extended radials of the antenna.
Never mount this or any antenna next to or near any electrical power lines.
This antenna is intended for amateur radio use only, and the person much hold a valid FCC Ham Radio license in order to legally transmit on the listed frequencies.
