Built a home brew J-Pole antenna. It is designed for 2 meter / 70 centimeter. It is made from 10' of 1/2" copper tubing, a couple of fittings, a coax connector, and a piece of 14 gauge copper wire.
The stand is a piece of steel pipe in a wooden stand that I rigged up. The driveway is sloped so it doesn't stand straight, but it is fine on a more level surface.
I used this calculator and tuned it for aproximately 145 MHz: http://www.hamuniverse.com/jpole.html
The main pole is about 58" long, the J is 19". They're separted by about 1.75" and the feed point is just under 2" from the base. I made a balun by wrapping 4 turns of the coax in a loop about 5" in diameter.
The SWR meter doesn't budge on the 2 meter band when doing a test transmit. On the 70 cm, it reads about 1.5, which is not ideal but in the workable range.
With this in the driveway here in High Point, I was able to hit the W4UNC (70cm) repeater (on 15-501 at the Chatham County Line ~46 miles distant) and I could hear talking but not really make out the K4ITL repeater in Garner (~84 miles away). Not bad for a few parts from Lowes and some scrap 2x4 in the garage.
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The stand is a piece of steel pipe in a wooden stand that I rigged up. The driveway is sloped so it doesn't stand straight, but it is fine on a more level surface.
I used this calculator and tuned it for aproximately 145 MHz: http://www.hamuniverse.com/jpole.html
The main pole is about 58" long, the J is 19". They're separted by about 1.75" and the feed point is just under 2" from the base. I made a balun by wrapping 4 turns of the coax in a loop about 5" in diameter.
The SWR meter doesn't budge on the 2 meter band when doing a test transmit. On the 70 cm, it reads about 1.5, which is not ideal but in the workable range.
With this in the driveway here in High Point, I was able to hit the W4UNC (70cm) repeater (on 15-501 at the Chatham County Line ~46 miles distant) and I could hear talking but not really make out the K4ITL repeater in Garner (~84 miles away). Not bad for a few parts from Lowes and some scrap 2x4 in the garage.
