The image below shows the VSWR profile of the included 'stock' antenna. Make no mistake, the stock antenna that manufacturers of all handheld radios from Icom, to Yaesu to TYT share the same overall profile. To interpret the data below in layman's terms, it shows:
- The 'dips' on the wave on this chart are where you need to be. The green vertical bands show the area of interest for most of our users. The trough of the dip should fall at or near the 3 value (the lower the better, and anything above 4-5 should be avoided). Shown below then, the stock antenna has acceptable VSWR (standing wave) when used in the range of 140-150 MHz (VHF), and 402 to 474 MHz (UHF). If you plan to transmit outside of these ranges, then you need another aftermarket antenna that is tuned to match the frequencies you are going to use, especially for VHF frequencies. Popular antennas on Amazon such as the 'Diamond', etc., are tuned for the HAM bands and are not suitable for commercial VHF frequencies that lodges, Gov't, specialists (guides, SAR, etc), and NGO's use.
In addition:Ā
- stock antennas are not made to withstand the rigors of outdoor field use for long, so think in terms of replacing them after the first operational season.
- stock antennas are not designed to be tuned by the consumer
- you cannot put our counterpoise (rat tail) on a stock antenna
- the chart below does not show reflected power
- the chart below does not show the wave propagation pattern
- tuned aftermarket antennas show better values for all of the above