On May 10, 2012 at 18:50, NFASTRO said...
I have nothing against the CM4228 (I am using it right now) or against many of the newer "HD" antennas that are re-packaged and look sleek for the benfefit of the consumer. Underneath, they all use the same old technology that was around fifty years ago.
This is because, as noted, physics is the same. In fact, let me point out that the original meaning of "state of the art" was "well, that's how we're doing it these days." This "old technology" is state of the art from the point of view of that definition and also from the newer point of view that "it's the best thing there is."
My point was that the laws of physics and electromagnetism still rule and no one has been able to make a revolutionary change in antennas to match the progress in tv's or computers.
I'm sorry, but it's just silly to expect that fixed laws of physics regarding frequencies, wavelengths, and electromagnetics will somehow change at the same time that we have gone from tubes to transistors to ICs to high-density ICs; and from tube displays to plasma and LCD. It's like expecting the cup to change from open side up to open side down because man went from the stone age to the modern age. A cup still must be open side up. Antennas follow fixed rules.
I guess I am waiting for someone to invent some sort of intelligent antenna that can give us ten times the gain of today's antennas.
Now, there's an idea: integrate the TV with the antenna and have the TV command mechanical changes to the antenna to optimize the signal!
With regards to the CM4228 and the multitude of clones, I have always wondered why the bowties are all the same length. Should some be constructed longer to receive lower frequencies, and some shorter to enhance higher frequencies? Dimensions and packaging are probably a problem with this design.
People will package whatever works, so no, it's not packaging. My favorite long-distance FM antenna came in an eight foot long box.
If I understand correctly, antennas of any particular length work optimally at one frequency, but they work nearly optimally at nearby frequencies and multiples of the fundamental. I guess this doesn't explain why a bowtie works so well over such a large range of frequencies, though.
As for length, yes, VHF antennas are always longer than UHF. In the ham world, the obvious example is that an 80 meter antenna is bigger than a 2 meter antenna. The AM band has wavelengths from almost 600 meters to about 200 meters... yet we've had antennas that work reasonably well over the entire range.