I’m working on 21 things that a ham should do after getting a license. My most recent project was better antennas for my handheld dual-band radio. The short antenna on such a radio is known as a “rubber duck” and like all short antennas, it is much less efficient than one that is resonant on the given frequency. The VHF and UHF ham bands have short enough wavelengths that resonant antennas are not unreasonably big. The simplest VHF resonant antenna is a quarter-wave ground plane antenna. This means that the radiator is one fourth of a wavelength long (two meters divided by 4 is roughly 20 inches) and that the radiator extends over an electrically conductive plane.

This is one of the simplest antennas a new ham can build and the ARRL even sent me plans for one in their welcome materials! There are lots of plans online for this antenna project. I ended up using ones from http://www.ccars.org/projects/2mgp/tech_2mgp.htm and http://www.hamuniverse.com/kc0ynr2metergppvc.html, but they are all substantially the same so you can just google “2 meter groundplane antenna”.

Construction

Soldering the center conductor to the SO-239 chassis mount connector was by far the hardest part. I started out thinking that I would use coat hangers for the radiating element as well as the radials, but I couldn’t for the life of me get the solder to stick to the coat hanger. The internet agrees with me that it is nearly impossible to solder coat hangers, with one site even going so far as to call the metallurgy of coat hangers a “dark art”. So, off to the hardware store for a short length of 10 gauge copper house wire. After stripping the insulation, I was able to get is soldered precariously onto the connector.

Attaching the radials was no problem using some screws and washers from the local hardware store. One of the best suggestions I saw online was to interlace the radials so that each wire passed underneath the next one around the circle. This made the radials much stronger and better aligned.

Performance

The antenna did everything I hoped for. There is a repeater about 15 miles from my house. The local ARES club hosts a net there each Sunday night. From my house, with just the rubber duck antenna, I could get into the repeater but couldn’t be copied. Other people nearby could hear me transmitting on the repeater input frequency, but I couldn’t be heard on the net. With the quarter-wave groundplane antenna hooked up to a coax jumper and just held up over my head with a short piece of PVC, I was able to be heard well on that local repeater.

With that success under my belt, I moved on to building a small yagi for the 440 MHz/70 cm band of another local repeater. More on that project later.