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Richard Clark wrote in message
No doubt you were "prevented." They couldn't hear you! I would tend to believe this account. Small vertical antennas next to the ground with no radials, will be just a tad better than a dummy load on that band. MK |
Mark Keith wrote:
"For DX transmitting on the lower bands, vertical polarization is the best way to go." In some cases. If that were always the case, why do commercial shortwave stations all use horizontal polarization for both point-to-point service and broadcasting? During my years in shortwave broadcasting, I never saw a single vertically polarized antenna used for HF transmitting. My experience is not unique. E.A. Laport was Chief Engineer, RCA International Division of Radio Corporation of America (RCA). For many years RCA was the largest short-wave communications organization in the world. In his book, "Radio Antenna Engineering", Ed Laport says: "The earliest high-frequency beam antennas used vertical polarization, but subsequent evolution has caused the almost universal use of horizontal polarization. There may be a reversion to vertical polarization in the future for certain applications." It was natural to try vertical polarization first for directional arrays as low and medium frequencies were first exploited for radio and these had to use vertical antennas. It was uneconomical to elevate horizontal antennas to heights necessary for sky wave performance and there is no ground wave propagation of horizontally polarized waves. The directional vertical antenna had been developed early in broadcasting by Brown, Lewis, and Epstein who did their RCA development work at HF for economy and convenience. Work was already in place for the earliest vertical HF beam antennas. These only evolved into the universal horizontal polarization at HF due to real advantages. Huge investments are made in HF transmitting antenna farms. I worked in a station that had a farm of over 400 acres of HF antennas, all horizontally polarized. This was no flip of a coin decision. The decision was based on the preponderance of experience at the time. Our paths were so long that we had to consider 2-hops in addition to a single hop on most. There surely must be instances where vertical polarization proves better than horizontal, but these are exceptions, not the rule. An example might be an antenna closely surrounded by the sea. A vertical array should be ideal. Best regards, Richard Harrison, KB5WZI |
Yuri, K3BU wrote:
"Recent studies found efficiency of various polarizations based on geographical location, related to geomagnetic fields (gyrofrequency). Do antenna modelimg programs adjust for gyrofrequencies? I can readily see that soil conductivity at a geographical location would affect efficiency and perhaps the polarization choice. John H. Nelson, RCA Short-Wave Radio Propagation Analyst, found that those signals which pass through or close to the auroral zone suffer the greatest degradation. If the signal must take a great circle route over the North Polar region, problems increase. Nelson also found that propagation here on the earth correlated with the relative positions of the planets in the solar system. Be this astronomy or astrology, it allowed Nelson to make pretty good radio propagation forecasts. See: "The Propagation Wizard`s Handbook", a "73" publication by J.H. Nelson. Best regards, Richard Harrison, KB5WZI |
Richard Harrison wrote:
There surely must be instances where vertical polarization proves better than horizontal, but these are exceptions, not the rule. Vertically polarized noise is about 10 dB higher than horizontally polarized noise at my QTH rendering a vertical antenna virtually useless for receiving compared to a horizontal antenna. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil Moore wrote:
Richard Harrison wrote: There surely must be instances where vertical polarization proves better than horizontal, but these are exceptions, not the rule. Vertically polarized noise is about 10 dB higher than horizontally polarized noise at my QTH rendering a vertical antenna virtually useless for receiving compared to a horizontal antenna. Sorry, forgot to say this was on 40m. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Here's my experience.
On transmit: 160 meters: 90 foot vertical is 20 dB better than 60 ft high inv vee 80 meters: 60 foot vertical is 10 dB better than 60 ft high inv vee 40 meters: 30 foot vertical is equal to 90 ft high inv vee 20 meters: 30 foot vertical is beaten by 90 ft high inv vee about 25% of the time 15 meters and up: Any dipole trounces any vertical. On receive: 160 and 80 meters: A low dipole trounces any vertical 40 meters and up: best receive antenna is best transmit antenna Rick N6RK There surely must be instances where vertical polarization proves better than horizontal, but these are exceptions, not the rule. Vertically polarized noise is about 10 dB higher than horizontally polarized noise at my QTH rendering a vertical antenna virtually useless for receiving compared to a horizontal antenna. Sorry, forgot to say this was on 40m. -- 73, Cecil http://www.qsl.net/w5dxp - 19 Different Servers! =----- |
What distances are you talking about? DX, local, etc...
"Rick Karlquist N6RK" wrote in message news:bBDJb.48697$I07.144572@attbi_s53... Here's my experience. On transmit: 160 meters: 90 foot vertical is 20 dB better than 60 ft high inv vee 80 meters: 60 foot vertical is 10 dB better than 60 ft high inv vee 40 meters: 30 foot vertical is equal to 90 ft high inv vee 20 meters: 30 foot vertical is beaten by 90 ft high inv vee about 25% of the time 15 meters and up: Any dipole trounces any vertical. On receive: 160 and 80 meters: A low dipole trounces any vertical 40 meters and up: best receive antenna is best transmit antenna Rick N6RK There surely must be instances where vertical polarization proves better than horizontal, but these are exceptions, not the rule. Vertically polarized noise is about 10 dB higher than horizontally polarized noise at my QTH rendering a vertical antenna virtually useless for receiving compared to a horizontal antenna. Sorry, forgot to say this was on 40m. -- 73, Cecil http://www.qsl.net/w5dxp - 19 Different Servers! =----- |
What distances are you talking about? DX, local, etc...
"Rick Karlquist N6RK" wrote in message news:bBDJb.48697$I07.144572@attbi_s53... Here's my experience. On transmit: 160 meters: 90 foot vertical is 20 dB better than 60 ft high inv vee 80 meters: 60 foot vertical is 10 dB better than 60 ft high inv vee 40 meters: 30 foot vertical is equal to 90 ft high inv vee 20 meters: 30 foot vertical is beaten by 90 ft high inv vee about 25% of the time 15 meters and up: Any dipole trounces any vertical. On receive: 160 and 80 meters: A low dipole trounces any vertical 40 meters and up: best receive antenna is best transmit antenna Rick N6RK There surely must be instances where vertical polarization proves better than horizontal, but these are exceptions, not the rule. Vertically polarized noise is about 10 dB higher than horizontally polarized noise at my QTH rendering a vertical antenna virtually useless for receiving compared to a horizontal antenna. Sorry, forgot to say this was on 40m. -- 73, Cecil http://www.qsl.net/w5dxp - 19 Different Servers! =----- |
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