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Dipoles, why height matters
In message ,
writes Ian Jackson wrote: In message , writes Ian Jackson wrote: snip Despite the obvious theory, and over 50 years in amateur radio, I still find it hard to believe that, in real life, an 80m dipole at (say) 20' ever really outperforms (at any distance) one at (say) 100'. Given the choice, I know which one I would choose! Try reading these: http://www.qsl.net/wb5ude/nvis/ http://en.wikipedia.org/wiki/Near_ve...idence_skywave http://www.w0ipl.net/ECom/NVIS/nvis.htm http://kv5r.com/ham-radio/nvis-antennas/ http://www.arrl.org/nvis Thanks, I'll certainly have a good read of those articles. But regardless of what they say, in a typical amateur scenario, I still reckon that at (say) 300 miles, an 80m signal from a dipole at 100' is likely to be stronger than one from one at 20' (or even at 60'). As 300 miles is at the upper end of NVIS and the lower end for skywave NVIS IS skywave - only that it's more straight up-and-down than at an angle. It's only a matter (literally) of degree, and there's no real point at which NVIS becomes 'normal' skywave. , it would be a crap shoot. NVIS distance is typically 30-400 miles. OK, let's make it a bit less - say 50 or 100 miles. I still feel that, in practice, a dipole at 100' would be unlikely to be less effective than at 20'. On the other hand, if you only want to lay down a signal out to less than 400 miles, there's no point in going to the trouble of putting the dipole at 100'. Apart from cost etc, this would also unnecessarily cause QRM to reception outside your intended target area. -- Ian |
Dipoles, why height matters
On 11/22/2014 1:07 PM, wrote:
Jerry Stuckle wrote: On 11/21/2014 8:56 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 8:19 PM, wrote: Jerry Stuckle wrote: snip I've also run dipoles - I got WAS on 75 meters from Iowa with an inverted VEE running from 50' to near ground. And I had a strong signal on the Iowa 75M SSB net. I have lots of strong signal reports from around the country on 6M AM running 3W into a 2 foot collapsible whip. Of course it was at the height of sunspot cycle 19 and says NOTHING about the effectiveness of the antenna. Which has absolutely nothing to do with your comment about a dipole on 75 meters. But you're too stoopid to understand that. But it has EVERYTHING to do with your comment about WAS. But you are so enraged about being correct you can not understand that. Nope. It has NOTHING to do with a dipole on 75 meters - which is the subject of this thread. You're just trying to derail the conversation so you don't have to admit you're wrong. Strawman arguement in an attempt to deflect the arguement from your WAS statements. Once again you try to change the subject so that you don't have to admit you are wrong. In case you haven't figured out - 6 meters and 80 meters are two entirely different bands with completely different propagation effects. Trying to tie the two together is just an attempt to deflect the conversation. Just like the troll you are. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Dipoles, why height matters
On 11/22/2014 1:09 PM, wrote:
Jerry Stuckle wrote: On 11/21/2014 8:58 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 8:22 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 5:22 PM, Wayne wrote: snip Along the lines of a "testimonial"... I once lived in the center of a state that had an active 75 meter net. At one point I was asked to be one of the net control stations because of my consistent strong signals within the net. The secret? A 75 meter dipole at 20 feet with 100 watts. On longer paths, of course, the "big boys" kicked my butt big time. Gee, according to jimp, your antenna should have "sucked". Which shows you are incapapble of understanding the difference between NVIS propagation and skywave propagation or anything else that I wrote. Nope, I understand them a lot better than you do. And his comments had NOTHING to do with what you said. According to you, his antenna "sucked". Period. No qualification. My god you are delusional when you are raging. Read your own words. YOU said it - not me. If you did understand it, you would know that what he said is TOTALLY consistant with what I wrote. And once again you are trying to weasel out of what you said. Just like a troll. My god you are delusional when you are raging. Once again you refuse to discuss the topic. Instead of admitting you are wrong, you are making ad hominim attacks. How like a troll. My god you are delusional when you are raging. Once again you refuse to discuss the topic. Instead of admitting you are wrong, you are making ad hominim attacks. How like a troll. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Dipoles, why height matters
On 11/22/2014 7:21 AM, Ian Jackson wrote:
In message , writes Ian Jackson wrote: snip Despite the obvious theory, and over 50 years in amateur radio, I still find it hard to believe that, in real life, an 80m dipole at (say) 20' ever really outperforms (at any distance) one at (say) 100'. Given the choice, I know which one I would choose! Try reading these: http://www.qsl.net/wb5ude/nvis/ http://en.wikipedia.org/wiki/Near_ve...idence_skywave http://www.w0ipl.net/ECom/NVIS/nvis.htm http://kv5r.com/ham-radio/nvis-antennas/ http://www.arrl.org/nvis Thanks, I'll certainly have a good read of those articles. But regardless of what they say, in a typical amateur scenario, I still reckon that at (say) 300 miles, an 80m signal from a dipole at 100' is likely to be stronger than one from one at 20' (or even at 60'). Yes, intuitively it certainly seems like the higher antenna will perform better. However, I have a chart about loop antennas that rates the 75 meter loop highest in NVIS gain at 25 feet high. I included the pdf file if it comes through. Mine at 33 feet makes a pretty good NVIS antenna. Will never know what it would do at 100 feet. |
Dipoles, why height matters
On 11/21/2014 7:32 PM, Jerry Stuckle wrote:
On 11/21/2014 8:19 PM, wrote: Jerry Stuckle wrote: snip I've also run dipoles - I got WAS on 75 meters from Iowa with an inverted VEE running from 50' to near ground. And I had a strong signal on the Iowa 75M SSB net. I have lots of strong signal reports from around the country on 6M AM running 3W into a 2 foot collapsible whip. Of course it was at the height of sunspot cycle 19 and says NOTHING about the effectiveness of the antenna. Which has absolutely nothing to do with your comment about a dipole on 75 meters. But you're too stoopid to understand that. Jeez, Take it easy Jerry. |
Dipoles, why height matters
Ian Jackson wrote:
In message , writes Ian Jackson wrote: In message , writes Ian Jackson wrote: snip Despite the obvious theory, and over 50 years in amateur radio, I still find it hard to believe that, in real life, an 80m dipole at (say) 20' ever really outperforms (at any distance) one at (say) 100'. Given the choice, I know which one I would choose! Try reading these: http://www.qsl.net/wb5ude/nvis/ http://en.wikipedia.org/wiki/Near_ve...idence_skywave http://www.w0ipl.net/ECom/NVIS/nvis.htm http://kv5r.com/ham-radio/nvis-antennas/ http://www.arrl.org/nvis Thanks, I'll certainly have a good read of those articles. But regardless of what they say, in a typical amateur scenario, I still reckon that at (say) 300 miles, an 80m signal from a dipole at 100' is likely to be stronger than one from one at 20' (or even at 60'). As 300 miles is at the upper end of NVIS and the lower end for skywave NVIS IS skywave - only that it's more straight up-and-down than at an angle. It's only a matter (literally) of degree, and there's no real point at which NVIS becomes 'normal' skywave. NVIS is generally defined as aiming the power straight up and the S in NVIS stands for "Skywave". So if you want to be pendatic, you are correct. However, if you look at the links above, the real world DOES make a distinction between NVIS and skywave. it would be a crap shoot. NVIS distance is typically 30-400 miles. OK, let's make it a bit less - say 50 or 100 miles. I still feel that, in practice, a dipole at 100' would be unlikely to be less effective than at 20'. The experience of all the world's militaries and those others who have done actual measurements come to a contrary conclusion. -- Jim Pennino |
Dipoles, why height matters
Jerry Stuckle wrote:
On 11/22/2014 1:07 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 8:56 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 8:19 PM, wrote: Jerry Stuckle wrote: snip I've also run dipoles - I got WAS on 75 meters from Iowa with an inverted VEE running from 50' to near ground. And I had a strong signal on the Iowa 75M SSB net. I have lots of strong signal reports from around the country on 6M AM running 3W into a 2 foot collapsible whip. Of course it was at the height of sunspot cycle 19 and says NOTHING about the effectiveness of the antenna. Which has absolutely nothing to do with your comment about a dipole on 75 meters. But you're too stoopid to understand that. But it has EVERYTHING to do with your comment about WAS. But you are so enraged about being correct you can not understand that. Nope. It has NOTHING to do with a dipole on 75 meters - which is the subject of this thread. You're just trying to derail the conversation so you don't have to admit you're wrong. Strawman arguement in an attempt to deflect the arguement from your WAS statements. Once again you try to change the subject so that you don't have to admit you are wrong. In case you haven't figured out - 6 meters and 80 meters are two entirely different bands with completely different propagation effects. Trying to tie the two together is just an attempt to deflect the conversation. Yet another strawman arguement; the pattern of a dipole expressed in terms of wavelengths is the same at 3 MHz and 3 GHz. And during sunspot peaks you get the same NVIS and skywave effects at 6M. And the whole point of the 6M statement was that QSL cards or WAS awards say absolutely nothing about antenna patterns. -- Jim Pennino |
Dipoles, why height matters
Jerry Stuckle wrote:
snip Once again you refuse to discuss the topic. Instead of admitting you are wrong, you are making ad hominim attacks. How like a troll. The only topic to discuss when you go off into one of your delusional rages and say I said things completly opposite to what I did say would be where you could get professional help for your raging delusions. -- Jim Pennino |
Dipoles, why height matters
On 11/22/2014 5:02 PM, wrote:
Jerry Stuckle wrote: On 11/22/2014 1:07 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 8:56 PM, wrote: Jerry Stuckle wrote: On 11/21/2014 8:19 PM, wrote: Jerry Stuckle wrote: snip I've also run dipoles - I got WAS on 75 meters from Iowa with an inverted VEE running from 50' to near ground. And I had a strong signal on the Iowa 75M SSB net. I have lots of strong signal reports from around the country on 6M AM running 3W into a 2 foot collapsible whip. Of course it was at the height of sunspot cycle 19 and says NOTHING about the effectiveness of the antenna. Which has absolutely nothing to do with your comment about a dipole on 75 meters. But you're too stoopid to understand that. But it has EVERYTHING to do with your comment about WAS. But you are so enraged about being correct you can not understand that. Nope. It has NOTHING to do with a dipole on 75 meters - which is the subject of this thread. You're just trying to derail the conversation so you don't have to admit you're wrong. Strawman arguement in an attempt to deflect the arguement from your WAS statements. Once again you try to change the subject so that you don't have to admit you are wrong. In case you haven't figured out - 6 meters and 80 meters are two entirely different bands with completely different propagation effects. Trying to tie the two together is just an attempt to deflect the conversation. Yet another strawman arguement; the pattern of a dipole expressed in terms of wavelengths is the same at 3 MHz and 3 GHz. And during sunspot peaks you get the same NVIS and skywave effects at 6M. And the whole point of the 6M statement was that QSL cards or WAS awards say absolutely nothing about antenna patterns. Once again you try to change the subject so that you don't have to admit you are wrong. In case you haven't figured out - 6 meters and 80 meters are two entirely different bands with completely different propagation effects. Trying to tie the two together is just an attempt to deflect the conversation. Just like the troll you are. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
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