The typical rubber duck antenna that is included with a hand-held transceiver is a 'loss' antenna, and it has about 5dB of 'loss'. (A dB is a 'decibel', which is power measurement relative to a reference - in this case the rated power output of the radio's transmitter.) What this means is that a Kenwood TK-3101 2-watt radio transmitter, when using a rubber 1/4 wave antenna, has an Effective Radiated Power (ERP) of about one-fifth (1/5) of two watts, or only .4 watts! The rubber duck antenna will induce additional loss if placed near a metal object like the bike's frame, for example. Not only does the rubber duck antenna induce loss on the transmit signal, but it significantly reduces the sensitivity of the receiver by the same ratio, as well. The rubber duck antenna is for convenience only, not performance. The big advantage to the Stealth Blade Antenna is that it affords a 2dB gain, or gives an ERP of about 3.16 watts (2 watts x 1.58 'gain') on the Kenwood radio, and that's a significant gain over the .4 watts with the rubber duck 1/4 wave antenna! Not only does the radio now have superior transmit range as compared to when using the rubber duck antenna, but the receiver's sensitivity is effectively improved by the same relative amount.
