Originally Posted by deltaguy
Last time I looked at the KRCR website, their recommendation for digital reception was, NO RABBIT EARS. What is one to use for indoor reception of RF 7?
You're supposed to use the Magic Antenna.
Pardon my sarcasm but I've been pondering this post for sometime. I've experimented with antennas for many years, mostly in ham radio, and I've seen the search for the magic antenna as a recurring theme. I'm not making fun of any person here, just the concept of the magic antenna as almost everyone who has played with antennas has embarked on this search.
What is a Magic Antenna? That is the antenna that is smaller and mounted much lower than a traditional and higher mounted antenna, often of an unconventional design, but performs as well or nearly as well as the latter.
In the ham radio world the search is often for a reduced sized antenna for 7 Mhz, 3.5 MHz, or 1.8 MHz, ground mounted that will work like a full sized antenna 100' or more in the air. The designs are endless and the mythology that grows up around some of them is vast. But under computer modeling, none of them show performance anywhere near the old standards.
The same thing is going on today for indoor antennas for DTV. Reports run the gambit from useless to great for just about any antenna. Why is this so?
If we assume that enough signal is getting inside a building for it to at least be possible to receive a DTV signal, then the problem we're left with is reflections - multipath.
Try imagining a signal entering a room from a couple different places and then bouncing off the walls and everything else inside. The room is full of crisscrossing signals from every direction. Further imagine that the reflections are not necessarily equal in amplitude at all points across the 5.4 MHz bandwidth occupied by the signal.
Now you have a room filled with weak spots and hot spots for all those reflections that are slightly out of time sync with each other.
Your mission, if you decide to accept it, is to position your antenna in the room where just one reflection reaches it, is strong enough across the entire 5.4 MHz bandwidth and where all the other reflections are weak enough so that the signal-to-noise ratio of the main signal is high enough so that your TV can decode the signal. Then try to find one position for all the other stations you wish to receive. This indeed can be Mission Impossible.
It's no surprise then that just about any antenna will work in some locations on some channels and not in other locations on other channels. It's also no surprise that antennas contorted into all sorts of positions that break all the rules of antenna design sometimes work. After all, what you're doing is not much different from moving your cell phone to find the hot spot with the most bars but that DTV is more sensitive to multipath so it makes the job even harder.
I'm sure some of these indoor antennas are worse than others, but none are the magic antenna that is as good or nearly as good as a traditional antenna on your roof above the trees and buildings. Beyond eliminating the truly bad ones, I don't think there is any indoor antenna that can be recommended with any certainty of success.