Full Quarter wave 2 meter handheld antenna

thingiverse

A quarter wave 2 meter antenna for a handheld ham band radio. Background: From our QTH, we're located near two repeaters that are over 18 miles distant. Our handheld can't consistently push a signal out to either of them. The standard Rubber Ducky is convenient but not ideal for propagation. We've been able to reach the repeaters with ease using our dipole above the roof on just one watt. My Solution: To improve our signal, we decided to create a simple 1/4 wave antenna from materials available at our homestead and shack. This way, we can have better propagation without having to purchase any additional equipment. The Materials We Used: * 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 added stiffness * Two printed parts: one ferrule to keep the aluminum tubing centered and attached to the So239 adapter, and another cap to secure everything in place Possible Substitutions: We considered using different materials, such as 4mm tubing or even a steel rod. However, we decided against it due to weight concerns. A brass bushing soldered onto a thin steel rod could also work, but we didn't have those materials available. Important Reminder: Make sure you have the necessary amateur radio license before transmitting on any handheld radios. Conclusion: After using this antenna for about 4 months, we've seen significant improvements in our signal strength. However, the downside is that it's longer and more difficult to use in a vehicle. Surprisingly, connecting to the repeater at 4 watts is better than at 8 watts with the Rubber Ducky. Resonant Length: For 146mhz, the resonant length of this antenna is approximately 19 3/4" from the top of the nut. Keep in mind that about an inch of aluminum is buried within the adapter. It's best to start with a longer length and gradually shorten it until you achieve optimal results.