If you're in a weak signal area, you might need more than an off-the-shelf antenna can provide. By stacking two eight-bay antennas, you can really pull in broadcasting from further away.
Short of dropping hundreds of bucks (and maybe more, these days), the best antenna you can buy for basic reception is an eight-bay. Although that's not bad, it's certainly not going to pick up stations from 90 or 100 miles away. And, of course you're thinking: who needs reception from the next city? The answer, though, might be you! If you don't have a good selection of HD local channels in your city [Hack #28] , a good antenna often can pick up stations from a nearby city. And because HD is an "either you got it or you don't" situation, if you have a strong antenna, you might be able to watch the Cowboys in HD after all.
When two identical antennas are mounted together, or ganged, pointed in the same direction, and wired together properly, there is a theoretical possibility of a 3dB improvement. That is, twice the signal power is delivered to the TV compared to what a single antenna would do. In practice, 2.5dB is readily achieved, as 0.5dB is typically lost in the combining mechanism. But if the two antennas are pointed in different directions (toward different stations), a 3.5dB penalty for each antenna is the likely result.
Further, these statements remain true regardless of whether the antennas have shared or separate amplifiers. For a shared amplifier, ...