While i forgot to look up line losses for RG-6 quad shield vs low loss foam twin-lead at work today, i just happened to run across an "antique" GC Electronics catalogue that i had handy from 1976 !!! In it, i can find a multitude of antennas that list extreme distance FM reception. One of them lists 220 miles on FM ( this antenna has a 110" reflector and an absolutely huge boom ), one lists 190 miles on FM with 29 elements / 111" boom, another lists 120 miles on FM with 21 elements on an 85" boom, another dedicated FM antenna lists 150 miles on FM using 19 elements, another lists 190 miles on a 95" boom, etc... Obviously, these ratings are probably best case scenario and probably just a bit optimistic at that. None the less, they state that reception of signals within the FM broadcast band is possible for WAY, WAY over 100+ miles. Obviously, this would require a proper antenna installation and both good receiving AND a solid transmitter signal to do so.
While some of you may find those figures hard to believe, i can at this very moment pull in a local low powered FM station that is appr 30 - 40 miles away from me with no problems whatsoever. While you say that this is NOTHING in terms of distance, i am doing it using a 6' piece of coax as an antenna with NOTHING connected to it. The coax is simply connected to the 75 ohm antenna jack and lays horizontally across a shelf. There is the typical "copper stub" exposed that one would normally have hanging out of an "F" connector and that is it. As such, i'm getting 30+ miles of FM reception in stereo on what is basically a 100% shielded conductor. In effect, this has less capture area than if i literally had a coat-hanger stuck in the antenna jack.
While it is true that i have relatively flat terrain between my location and the transmitter, if you can't get 100+ miles out of a KICK ASS directional antenna installation mounted outdoors and up relatively high and in the open, you better think about buying some better gear or moving out of the caves down in the valley. There is NO reason other than having a poor installation and / or poor quality receiving gear that you should not be able to pick up a multi-kilowatt station 100+ miles away. That is, unless you have other nearby stations operating on the same frequency.
If local stations are not on the same exact frequency but are close enough to cause interference to the distant ones that you want to hear, you need to increase the selectivity and adjacent channel rejection of the tuner you are using. You can do this via the use of what is called a "pre-selector" in the radio communications field. Magnum Dynalabs markets one of these devices and markets it under the name of "Signal Sleuth". This device tightens up the front end of the receivers by fine tuning the "Q" or bandwidth of the received signals. As such, you can effectively "null out" unwanted signals simply by fine tuning the filter. Keep in mind that you would have to fine tune these filters for each individual station or frequency that you were trying to pull in.
Besides being able to "pre-select" the quality of the signal being fed into the tuner, it can also increase the quantity i.e. "amplify" it. This should increase the signal to noise ratio and improve stereo separation.
For the record, i'm pulling in that local "weak station in the distance" using a tuner that i paid $29 for from a pawn shop in Indiana. Sean
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