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vert vs dipole gut comparison
On Mon, 20 Mar 2006 11:32:05 -0800, Roy Lewallen
wrote: A fellow could come to the conclusion that "this ain't exactly easy". HA! It isn't. The best antenna for transmitting is the one which produces the loudest signal at the other station. The best antenna for receiving is the one which produces the best signal/noise ratio at your station. The two are often different, because they're determined by different antenna characteristics. So for starters, you can have two "best" antennas for each station you want to contact, and that "best" will vary with the skip elevation angle, local noise level, and directions and angles the noise is coming from. Just was I was thinking when I prompted the "works" definition. I should not be surprised if many observations indicate the better antenna for tx is different from the better antenna for rx. I am not trying to question reciprocity, but there are several factors, ambient noise at the rx site probably being the most significant. Key thing is, works is not adequately defined by making one or a few DX QSOs!. Mike, perhaps you need to formalise your "works" criteria with your current experience, identifying what you need to record, before making too many more observations. I agree with Roy, for each antenna, rx main figure of merit S/N (crudely S units between ambient noise and signal), and on tx, the other stations observed S meter reading. (Whole log of issues there... but a rough start supported by the current RST reporting scheme.) Owen -- |
vert vs dipole gut comparison
Is the polarity of the sending station and receiving station relevant
to this discussion?? That is, a dipole sending station and a dipole receiving station would tend to out perform a dipole sending station and a vertical receiving station and vice versa? Are there more stations with dipoles than stations with verticals? |
vert vs dipole gut comparison
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vert vs dipole gut comparison
Cecil Moore wrote:
wrote: Is the polarity of the sending station and receiving station relevant to this discussion?? Yes on ground wave VHF/UHF. No on HF skip. Oops, lest some nitpicker jump in, I should have said "surface wave", not "ground wave". And I probably should have included a "usually" while I was at it. -- 73, Cecil http://www.qsl.net/w5dxp |
vert vs dipole gut comparison
ORIGINAL MESSAGE:
Cecil Moore wrote: Cecil Moore wrote: wrote: Is the polarity of the sending station and receiving station relevant to this discussion?? Yes on ground wave VHF/UHF. No on HF skip. Oops, lest some nitpicker jump in, I should have said "surface wave", not "ground wave". And I probably should have included a "usually" while I was at it. -- *********** REPLY SEPARATOR *********** Nitpicker alert: 1. You should have not limited the "NO" to HF. Six meters is also a "NO" for ionospheric skip. 2. Polarity of the signal for ground wave (not surface or space wave) is indeed important. Vertical polarization works best. Horizontal is rapidly attenuated. Bill, W6WRT |
vert vs dipole gut comparison
"Gary Schafer" wrote in message ... You want both antennas if you can do it. Anyone who declares one or the other the winner is simply wrong. - 73 de Mike KB3EIA - I did some tests a couple of years ago on 10 meters between vertical and horizontal on an 1800 mile path. It seems that there is quite a bit of rotation in polarity of the signal from minute to minute. I tried right and left hand circular to confirm that it was rotation. 73 Gary K4FMX Cross-polarization losses are in the neighborhood of 10-20 dB at VHF and above. With my license, I cannot do HF, so others may chime in with those numbers. Assuming ... there's that word ... that the random polarization variations ("rotations") are around some central figure, during for a given QSO, then one antenna will work better -- the one that happens to be optimum for that path and for the antenna on the other end of the QSO. There exists a phenomenon that I do not understand well, called Faraday rotation, where an EM wave passing through a magnetic field will undergo a polarization "alteration", so to speak. Thus, two verticals on the ends of a long-distance QSO might not perform as well as if one were a vertical and the other a horizontal -- due to the Earth's magnetic field. John KD6VKW |
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