Building antenna's has been a favourite part of ham radio (amateur radio) and electronics. Most antenna's can be built from items around the house and yet work just as well as store bought models. Building scanner antenna's can be both educational and informative as you are able to tune in aeroplane, police, fire, rescue, and ham radio communications. Following a few steps will help you to know how to build a multi-band scanner antenna that you will be proud of and ready to show to all of your friends as you listen in on the airwaves.
Cut the rods to measure 635 mm (25 inches) in length with the wire cutters.
Sand about 50 mm (2 inches) on one end of each of the five rods. This will remove any paint or coatings that would prohibit a good soldering joint and connection.
Mount the SO-239 connector securely in the table vice with the male connector pin facing up.Be sure to not over tighten the connector and damage it.
Take one of the rods and apply just a small about of flux to the sanded end. Apply just enough to make a thin coating over the sanded area. The flux will help the solder to adhere to the rod and connector making a good connection.
Insert the end of the rod with the flux on it into the hollow centre pin on the end of the connector. Hold this steady as you solder in the step below.
Solder the rod to the connector pin, applying just enough solder to coat the connection evenly on all sides. Be sure to not over heat the connector to avoid melting the plastic insulator inside the connector.
Use the needle nose pliers to bend a small loop in the sanded end of each of the remaining four rods This loop will form a hole to allow us to mount the rods to the connector.
Insert a bolt though each hole/loop in the rod and using the screwdriver and pliers, mount one rod to each of the four holes on the four corners of the connector. Tighten each bolt and nut to a snug fit.
Remove the connector from the table vice and hold it steady in one hand. Using the pliers, bend each of the four rods on the corners of the connector downward to a 45 degree angle. Check each of the bolts and nuts to make sure they are snug tight.
Apply the clear silicone to the top of the connector and over the bolts to protect them from any outside elements or moisture.
Connect the cable from the scanner to the SO-239 connector.
Wear safety goggles to prevent injury to the eyes when working with the antenna rods. Never install this or any antenna next to or near any power lines as this could result in serious injury. This antenna is intended for listening purposes only, and all guidelines for monitor police or emergency frequencies should be following in your local area. Avoid contact with the end of the soldering gun/iron as this is very hot and could result in a serious burn. Always allow the soldering gun/iron 20-30 minutes to cool down before storing away.
Things you need
- Five 3mm (1/8 inch) copper rods (635 mm (25 inches each).)
- SO-239 connector
- 4 stainless steel bolts & nuts (size #6)
- Soldering gun/iron
- Needle nose pliers
- Table vice
- Clear silicone sealant
- 100 grit sandpaper
- Safety glasses
- Wire cutters
- Measuring tape