Full Quarter wave 2 meter handheld antenna

thingiverse

A quarter wave 2 meter antenna for a handheld ham band radio. Background: From our QTH. A handheld can't push a signal out to either of the two nearest repeaters with any consistency. Both of these repeaters are over 18 miles distant. We can get there with the dipole above the roof on one watt. The standard Rubber Ducky is convenient but not ideal for propagation. My solution: Make a simple 1/4 wave antenna from materials in my homestead and shack. The materials: A SMA female to SO239 adapter A stick of 5/32" aluminum tubing. The nut from a PL-259 connector A 3mm round carbon rod or tube (for stiffness) 2 printed parts a Ferrule to keep the aluminum tubing centered and attached to the So239 adapter. The second printed part to form a cap. Possible substitutions: Would be to use 4mm tubing or even rod. Steel rod is too heavy. but it would work. Perhaps a brass bushing soldered onto a thin steel rod would work. At the frequency use the rf current is carried in the skin of the antenna conductor. The reason that my antenna is what is is because I had all the materials at hand from other projects. Caution! Do not transmit on one of these radios unless you have the necessary amateur radio license. It is no joke. Conclusion: I have been using this antenna for about 4 months at present. The down side to this antenna is that it is long is more difficult to use in a vehicle. The connection to the repeater is better on 4 watts than at 8 watts on a rubber ducky. The resonant length for this antenna is about 146mhz is 19 3/4" from the top of the nut, longer than what I would have predicted but shorter would move the resonant point higher. Keep in mind that the aluminum has over an inch buried in the adapter. Start long and decrease till best.