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in his reply. Most of the situations he references were actually or likely using verticals... First off, anecdotal stories are just that, anecdotal. You need to be a little more convincing to dispute what models like NEC-4 are saying. Also, you also need to objectively examine some of the statements you just made... >Antennas were low dipoles(20-30 ft. high) and a windom > 20 ft. high at one end and 35 ft. high at the other. My output power was > about 15-30 watts on 10-20 meters. I worked piles of dx, on cw, So what's your point? I was recently at N6BT's house using a 100w GE light bulb on 10m, and we were able to work DX too. By just going by anecdotal information, I could make the following claims: * miniature antennas are excellent performers * The antenna only needs to be 3' high * 100w will work all the DX I can hear (which isn't much on a light bulb) Obviously, I would be highly misinformed and misled by my observations based on the limited experience of using the light bulb, regardless of how well I thought it "worked". What is missing is a reliable reference with which to compare my observations. >i found > the propagation to be excellent, anywhere i went. My power output was 100 > watts and my antennas were either verticals or sloping dipoles. Huh? Thank you for supporting that vertically polarized antennas over salt water are good antennas. (BTW, sloping dipoles have a large vertical polarization component). > In 1932 Bell Labs conducted test to determine where to locate shore > stations for communicating with ships at sea. These tests were conducted > in the 66 and 33 meter bands, under both day and night conditions.They > reported" attenuation of 8 db to 12 db is observed at a distance of one > mile inland for both 33 and 66 meter transmissions." What types of antennas were used? There is not enough info given here to draw any reliable conclusions. If they were verticals, then it makes sense (see below comment). > reminded me that when i was a kid and broadcast band dx'ing, i logged > WAPE in Jacksonville ,Fl. while living in Morehead City, N.C. In the 60's > and 70's, whenever i went home to visit my parents, i'd frequently look > for WAPE on the car radio(680 khz. if i remember correctly).At and around > my parents house(300 yds. from a salt water sound, i could receive it. > But a mile further inland, it became unreadable. Again, evaluate what you just said. Your statement seems out of place if you are trying to use it to support the horizontal enhancement theory you THINK is correct. AM broadcast stations are vertically polarized. And most car antennas use vertical whips (vertical polarization). The ground within 300 yards (surely a rough approximation) could have a water table that was near the surface and at least brackish, making a much improved ground for vertically polarized signals than a mile inland. (The ground condition applies to receive antennas, as well as transmitting.) I have no doubt that WAPE's signal was enhanced by the ocean. Take a portable short wave radio with a vertical whip and go to the ocean. Tune in a good ham signal, and start walking away from the water. The signal will drop off dramatically in a very short distance. Also, try turning the antenna horizontal and repeat the test of walking away from the ocean and see what happens... FYI - I have installed well over 100 vertical antennas on the ocean in my various contest DXpeditions, and have also run numerous tests (in controllable conditions) to examine the performance of verticals vs. Yagi's over salt water. In all cases, the verticals had the predicted gain over the horizontal array, which to me is a good argument that the antenna models have it right (besides, before I even said one word to this reflector, I called a bunch of respected ham antenna and propagation gurus - I'm friends with them all - and confirmed that horizontal polarization does not get any enhancement from salt water). Unfortunately in ham radio, the following quote is all too common "These are the conclusions upon which we based our facts." (by Adlai Stevenson). Before anyone else uses anecdotal info, I suggest you go to the ARRL handbook, antenna manual, etc to read up on antennas and propagation. Horizontal antennas do not gain any efficiency over salt water. Kenny K2KW PS for a little more info on verticals, visit my web site at: http://pages.prodigy.net/k2kw and look at the 6Y2A page. -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. Force 12 Web site: http://www.qth.com/force12 Submissions: send to Force12Talk@qth.com To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk For problems with the list, contact force12@qth.com |
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