When the Yagi is on 20m, there are two nicely spaced elements and there is gain of 6.6 dBi free space, and front-to-rear ratio of 21dB. What does this mean? As it turns out the laws of physics and the allocation of ham bands collide to help us out. In other words, the signal is NOT degrading – the characteristics of the antenna change as you adjust through the bands due to spacing of the elements. In the case of a SteppIR Yagi, our antennas adjust to the exact length required at any given frequency. Of course, all of those methods lead to significantly reduced performance when compared to a single frequency Yagi. There would normally be a caveat to this, at least with a fixed length aluminum Yagi – the antenna would have greatly limited bandwidth – roughly 120 Khz! This would be a highly impractical design since traditional fixed length Yagis are single-frequency devices – the bandwidth is very narrow unless you use traps, interlacing or simply add more elements in order to “trick” the radio into thinking it is resonant. 1 wavelength or less, the antenna will achieve gain performance that is quite high for a 2 element Yagi, more like the performance expected from a 3 element Yagi. When placing a parasitic element very close to a driven element, approximately. This antenna functions in a manner that would normally be consistent with a three element Yagi, due to its unique 57” (1.45m) boom length. The SteppIR two element 20m-6m Yagi has a small profile, but it offers big performance.
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