Off-Center Fed Dipole Police Scanner Antenna

Here’s a weekend project that will keep you busy for a moment and will give you a very nice police scanner antenna. This antenna is called an Off-Center Fed Dipole. The assembly is fairly easy and receive capability is fantastic. It took me a few minutes to put this scanner antenna together because I already had the parts on hand.

I had a skinny board to work with. PVC pipe will work also. Anything light and non conductive will do the job. There has to be a place to attach the balun transformer and there has to be something to attach the antenna itself to. I nailed my skinny board to a 2X4. The 2X4 was nailed to another 2X4 to get extra height. It went smooth for me this time.

The dipole will require two pieces of wire or aluminum rods. The measurements are: 48 inches for one of the elements and 18 inches for the other one. It doesn’t have to be exact. I had some aluminum rods on hand. The first aluminum rod was 19 inches and the second rod was 52 inches.

I used a 75 to 300 ohm TV Balun Transformer (Push-On F Type Balun) for the feed point. I had to have a F Female To F Female Coax Cable Joiner (20 Pack) to fit snug into the transformer. I used small pieces of300 ohm TV wire to connect the transformer to the aluminum rods. I suppose any wire would work, but smaller wire is much easier to deal with.

I used this for the connection to the scanner — Mediabridge Coaxial Digital Audio Video Cable – (50 Feet) – Triple Shielded, F-Pin to F-Pin with Easy Grip Connector Caps.

I used the F-Female to BNC-Male Adapter 25-7500 to connect my TV coax cable to my police scanner.

I always use black electric tape on all connections. It works for me. If I want to get a better seal, I use the Permatex 80050 Clear RTV Silicone Adhesive Sealant, 3 oz.. This is a good product.

This was a very easy project and the results were excellent I must say. There are a few pointers I’ve learned about antennas in general. There will usually be a sweet spot in the yard for better receive. If you add height, subtract height, or just move the antenna 30-50 feet either way, the results will vary. The sweet spot will give one the desired frequencies.

I was surprised to learn that if I put this on a tower and get some elevation, I could actually pull in some digital television signals. I have a dedicated HDTV coat hanger antenna established, so I really didn’t need another one. It’s nice to know that these things work if in a pinch.

Here are my final thoughts on the Off-Center Fed Dipole Scanner Antenna. The receive was as good as any commercial scanner antenna I’ve ever tried and probably better than most. I was very impressed with this scanner antenna. The object is to make the antenna light, sturdy, reliable, and flexible to work with. This homebrew antenna was very nice to work with. It’s definitely a keeper.