Q: Who are you?
My name is George Kostopoulos, I currently hold a General Class amateur and GMRS radio licenses, and my amateur callsign is KO4HVI.
Q: What makes your antenna special?
My folding, quarter wave, ground plane antennas are properly sized for their tuned band. This means more of your signal gets out and is not reflected back to potentially damage your radio or be wasted as heat. They are also sensitive receiving antennas. In addition to their performance, the one-piece folding design makes it ideal for easy deployment and storage in a backpack or radio bag. The materials are high quality. The antenna wire polyethylene coated copper for abrasion resistance and is made in the USA. The body is 3D printed by me from UV and weather resistant plastic and is filled with a weatherproof polymer. The connector is made by Amphenol, known for their rugged RF connectors. The radial separator struts are also 3D printed by me from a flexible, yet durable, UV resistant plastic. All the exposed hardware is nickel plated brass or aluminum and is corrosion resistant. The antenna is designed to be rugged, weather-resistant, easy to use and store, with no loose parts to lose.
Q: Does your antenna need ground radials?
No. The three radials coming out of the side of the hub are the ground radials. The antenna behaves like a dipole antenna in that respect. Also like a dipole, no choke is required to prevent your feed line from radiating RF energy.
Q: Why do you use a BNC connector instead of SO-239 / SMA / N / etc.?
I use BNC because it is common on portable radios and allows quick connect/disconnect, even in the dark.
Q: For your 2m antenna, why doesn't it also work well on the entire 70cm band?
Many 2m antennas advertise they also work on 70cm. This is partially true. In the USA, the 2m band runs from 144 MHz to 148 MHz and the 70cm band is 420 MHz to 450 MHz. A quarter-wave antenna is also resonant at three times its tuned frequency, where it works as a three-quarter-wave antenna. Three times 144 MHz is 432 MHz and three times 148 MHz is 444 MHz, so an antenna which is resonant for 2m is also resonant for the upper portion of 70cm. As a three-quarter-wave antenna, it also sends more of its signal upward and less toward the horizon. Dual-band antennas that have low SWR across both the 2m and 70cm bands use coils, traps, or other matching sections, which makes them a compromise on both bands. It is important to note that some radios are sensitive to SWR higher than 1.5:1. BTech, for example, warns in its mobile radio manual to use an antenna with an SWR of 1.5:1 or less, that reflected power from an antenna not tuned for the frequency in use can damage the radio, and that transmitting with high SWR can void warranty support. Transmitting under approximately 440 MHz in the 70cm band through a typical 2m antenna can exceed that limit. In fact, many dual-band radios don't transmit under 430 MHz for the 70cm band.
Q: I'm having issues with your antenna. Can you help me?
Yes. Contact me using one of the methods listed on the Contact page, and I'll help you solve the issue.