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Follow up to Spike ;Bent dipoles?
On 05/12/2015 18:53, wrote:
In rec.radio.amateur.antenna Spike wrote: On 05/12/2015 03:40, wrote: In rec.radio.amateur.antenna Spike wrote: On 03/12/2015 12:45, Brian Howie wrote: By coincidence my morning training run took me near the EDN NDB http://www.b-howie.demon.co.uk/lfbcon.htm It's a top loaded vertical, but looking over the fence, I could see a lot green earth wire radials on the surface. It's possible there are buried ones too , but there are only about 6 and they can't be more than 15ft long, For the beacon to be of maximum use, they'll need a good sky-wave signal; it sounds like the visible radials are there to provide a DC path to earth probably in association with a ground spike, rather than for getting the main lobe lowered. Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That's amazing. So all those aircraft at 35000 feet in its service area can't hear the beacon? If it didn't have sky wave, it would merely be a ground-wave beacon, not much use as there aren't that many airports within 35 miles of Edinburgh, and the aircraft captains would know where they were anyway. OK, I see the problem, you don't know what "skywave" means. To be refracted back, the wave has to reach the relevant layer. https://en.wikipedia.org/wiki/Skywave BTW, at 35,000 feet, the propagation mode is line of sight out to 265 miles. And? Sky wave propagation was discovered when amateurs started using frequencies greater than 200 meters. I've known that since 1956, but thanks for the reminder. What's interesting here is now much of the radiated power goes sky-wards, and how much goes into surface wave. But apparently no-one's ever thought to determine this, so it'll remain a mystery. The term for that is the vertical pattern and any antenna analysis program will show it. There have been LOTS of studies to determine the optimum vertical angle for skywave propagation if that is what you are talking about. Nope. -- Spike "Crime butchers innocence to secure a throne, and innocence struggles with all its might against the attempts of crime" - Maximilien Robespierre |
Follow up to Spike ;Bent dipoles?
In rec.radio.amateur.antenna Spike wrote:
On 05/12/2015 18:53, wrote: In rec.radio.amateur.antenna Spike wrote: On 05/12/2015 03:40, wrote: In rec.radio.amateur.antenna Spike wrote: On 03/12/2015 12:45, Brian Howie wrote: By coincidence my morning training run took me near the EDN NDB http://www.b-howie.demon.co.uk/lfbcon.htm It's a top loaded vertical, but looking over the fence, I could see a lot green earth wire radials on the surface. It's possible there are buried ones too , but there are only about 6 and they can't be more than 15ft long, For the beacon to be of maximum use, they'll need a good sky-wave signal; it sounds like the visible radials are there to provide a DC path to earth probably in association with a ground spike, rather than for getting the main lobe lowered. Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That is ground wave propagation; I'd give you a link but you obviously prefer to pull crap out of your ass to reading links. That's amazing. So all those aircraft at 35000 feet in its service area can't hear the beacon? If it didn't have sky wave, it would merely be a ground-wave beacon, not much use as there aren't that many airports within 35 miles of Edinburgh, and the aircraft captains would know where they were anyway. OK, I see the problem, you don't know what "skywave" means. To be refracted back, the wave has to reach the relevant layer. Didn't read the link below, did you? https://en.wikipedia.org/wiki/Skywave BTW, at 35,000 feet, the propagation mode is line of sight out to 265 miles. And? And "those aircraft at 35000 feet" are receiving the beacon through line of sight propagation, not skywave. Sky wave propagation was discovered when amateurs started using frequencies greater than 200 meters. I've known that since 1956, but thanks for the reminder. Perhaps you should have read more in 1956 to understand what the term means. What's interesting here is now much of the radiated power goes sky-wards, and how much goes into surface wave. But apparently no-one's ever thought to determine this, so it'll remain a mystery. The term for that is the vertical pattern and any antenna analysis program will show it. There have been LOTS of studies to determine the optimum vertical angle for skywave propagation if that is what you are talking about. Nope. Then you are ignorant of antenna analysis software and vertical radiation patterns? -- Jim Pennino |
Follow up to Spike ;Bent dipoles?
wrote:
In rec.radio.amateur.antenna Spike wrote: On 05/12/2015 18:53, wrote: In rec.radio.amateur.antenna Spike wrote: On 05/12/2015 03:40, wrote: In rec.radio.amateur.antenna Spike wrote: On 03/12/2015 12:45, Brian Howie wrote: By coincidence my morning training run took me near the EDN NDB http://www.b-howie.demon.co.uk/lfbcon.htm It's a top loaded vertical, but looking over the fence, I could see a lot green earth wire radials on the surface. It's possible there are buried ones too , but there are only about 6 and they can't be more than 15ft long, For the beacon to be of maximum use, they'll need a good sky-wave signal; it sounds like the visible radials are there to provide a DC path to earth probably in association with a ground spike, rather than for getting the main lobe lowered. Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That is ground wave propagation; I'd give you a link but you obviously prefer to pull crap out of your ass to reading links. That's amazing. So all those aircraft at 35000 feet in its service area can't hear the beacon? If it didn't have sky wave, it would merely be a ground-wave beacon, not much use as there aren't that many airports within 35 miles of Edinburgh, and the aircraft captains would know where they were anyway. OK, I see the problem, you don't know what "skywave" means. To be refracted back, the wave has to reach the relevant layer. Didn't read the link below, did you? https://en.wikipedia.org/wiki/Skywave BTW, at 35,000 feet, the propagation mode is line of sight out to 265 miles. And? And "those aircraft at 35000 feet" are receiving the beacon through line of sight propagation, not skywave. Sky wave propagation was discovered when amateurs started using frequencies greater than 200 meters. I've known that since 1956, but thanks for the reminder. Perhaps you should have read more in 1956 to understand what the term means. What's interesting here is now much of the radiated power goes sky-wards, and how much goes into surface wave. But apparently no-one's ever thought to determine this, so it'll remain a mystery. The term for that is the vertical pattern and any antenna analysis program will show it. There have been LOTS of studies to determine the optimum vertical angle for skywave propagation if that is what you are talking about. Nope. Then you are ignorant of antenna analysis software and vertical radiation patterns? Jim doing a Jeff here and tearing Spike *yet another* new arsehole. Excellent work, OM. -- STC // M0TEY // twitter.com/ukradioamateur |
Follow up to Spike ;Bent dipoles?
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Follow up to Spike ;Bent dipoles?
In rec.radio.amateur.antenna Spike wrote:
On 06/12/2015 00:06, wrote: snip Your problem, or at least one of them, is that your first response included this statement: "Sky wave propagation doesn't happen at those frequencies for all practical purposes." I let this slide in the interests of discussion, but seeing as you wish to nit-pick and be rude, we'll revisit this by my asking you what you meant, as you are implying that there is in fact some form of skywave at these low-MF Aeronautical beacon frequencies. Please explain. I see you finally read the link so now you think you are going to sharp shoot the original post. BTW, "for all practical purposes" is synonymous with "unlikely to ever happen". While doing that, please also explain what you think it is that causes the claimed variations in the ground wave than enable DX beacon hunters to hear such stations at very long ranges. Search for "ground wave propagation" and read up on it. The relevant quotes are he Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That is ground wave propagation; I'd give you a link but you obviously prefer to pull crap out of your ass to reading links. TIA -- Jim Pennino |
Follow up to Spike ;Bent dipoles?
On 06/12/2015 18:29, wrote:
In rec.radio.amateur.antenna Spike wrote: On 06/12/2015 00:06, wrote: snip Your problem, or at least one of them, is that your first response included this statement: "Sky wave propagation doesn't happen at those frequencies for all practical purposes." I let this slide in the interests of discussion, but seeing as you wish to nit-pick and be rude, we'll revisit this by my asking you what you meant, as you are implying that there is in fact some form of skywave at these low-MF Aeronautical beacon frequencies. Please explain. I see you finally read the link so now you think you are going to sharp shoot the original post. BTW, "for all practical purposes" is synonymous with "unlikely to ever happen". You don't seem to know whether or not sky-wave exists at these frequencies. 'Practically', sky-wave would be unreliable for NDB working, but that doesn't mean to say sky-waves don't exist. When you make up your mind about the topic, let me know what your answer is. To help you, there is a shed-load of information out there on MF sky-wave propagation. While doing that, please also explain what you think it is that causes the claimed variations in the ground wave than enable DX beacon hunters to hear such stations at very long ranges. Search for "ground wave propagation" and read up on it. I can't take that from someone who doesn't know that sky-wave exists at MF. Your variable ground-wave is a hoot. The relevant quotes are he Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That is ground wave propagation; I'd give you a link but you obviously prefer to pull crap out of your ass to reading links. You're a troll, aren't you? -- Spike "Crime butchers innocence to secure a throne, and innocence struggles with all its might against the attempts of crime" - Maximilien Robespierre |
Follow up to Spike ;Bent dipoles?
Spike wrote:
On 06/12/2015 18:29, wrote: In rec.radio.amateur.antenna Spike wrote: On 06/12/2015 00:06, wrote: snip Your problem, or at least one of them, is that your first response included this statement: "Sky wave propagation doesn't happen at those frequencies for all practical purposes." I let this slide in the interests of discussion, but seeing as you wish to nit-pick and be rude, we'll revisit this by my asking you what you meant, as you are implying that there is in fact some form of skywave at these low-MF Aeronautical beacon frequencies. Please explain. I see you finally read the link so now you think you are going to sharp shoot the original post. BTW, "for all practical purposes" is synonymous with "unlikely to ever happen". You don't seem to know whether or not sky-wave exists at these frequencies. 'Practically', sky-wave would be unreliable for NDB working, but that doesn't mean to say sky-waves don't exist. When you make up your mind about the topic, let me know what your answer is. To help you, there is a shed-load of information out there on MF sky-wave propagation. While doing that, please also explain what you think it is that causes the claimed variations in the ground wave than enable DX beacon hunters to hear such stations at very long ranges. Search for "ground wave propagation" and read up on it. I can't take that from someone who doesn't know that sky-wave exists at MF. Your variable ground-wave is a hoot. The relevant quotes are he Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That is ground wave propagation; I'd give you a link but you obviously prefer to pull crap out of your ass to reading links. You're a troll, aren't you? Gotten to, and rattled. That new arsehole you've been torn must sting a little, OM! -- STC // M0TEY // twitter.com/ukradioamateur |
Follow up to Spike ;Bent dipoles?
In rec.radio.amateur.antenna Spike wrote:
On 06/12/2015 18:29, wrote: In rec.radio.amateur.antenna Spike wrote: On 06/12/2015 00:06, wrote: snip Your problem, or at least one of them, is that your first response included this statement: "Sky wave propagation doesn't happen at those frequencies for all practical purposes." I let this slide in the interests of discussion, but seeing as you wish to nit-pick and be rude, we'll revisit this by my asking you what you meant, as you are implying that there is in fact some form of skywave at these low-MF Aeronautical beacon frequencies. Please explain. I see you finally read the link so now you think you are going to sharp shoot the original post. BTW, "for all practical purposes" is synonymous with "unlikely to ever happen". You don't seem to know whether or not sky-wave exists at these frequencies. 'Practically', sky-wave would be unreliable for NDB working, but that doesn't mean to say sky-waves don't exist. When you make up your mind about the topic, let me know what your answer is. To help you, there is a shed-load of information out there on MF sky-wave propagation. The term is "skywave" and it is not known to happen below 500 kHz. While doing that, please also explain what you think it is that causes the claimed variations in the ground wave than enable DX beacon hunters to hear such stations at very long ranges. Search for "ground wave propagation" and read up on it. I can't take that from someone who doesn't know that sky-wave exists at MF. Once again, the term is "skywave". Define MF; there is no exact frequency where skywave ceases to exist, but it has not been observed below 500 kHz. That does not mean that under some extreme ionospheric conditions is can not happen, it means no one has ever seen it happen. Your variable ground-wave is a hoot. The term is "ground wave" and ALL propagation modes are variable due to many reasons; a heavy rainstorm will effect ground wave propagation as it changes the ground conductivity. The relevant quotes are he Sky wave propagation doesn't happen at those frequencies for all practical purposes. Tell that to the beacon DX hunters. That is ground wave propagation; I'd give you a link but you obviously prefer to pull crap out of your ass to reading links. You're a troll, aren't you? Says someone that can not even use the correct terms. -- Jim Pennino |
Follow up to Spike ;Bent dipoles?
On Mon, 7 Dec 2015 01:17:34 -0000, wrote:
The term is "skywave" and it is not known to happen below 500 kHz. I beg to differ. The current issue of QEX has an article on a WWVB 60 KHz frequency standard: http://www.arrl.org/files/file/QEX_Next_Issue/2015/Nov-Dec_2015/Magliacane.pdf On Pg 15 is the section on 60 KHz propagation: LF radio propagation is substantially different from that which exists at higher frequencies. Its remarkable stability and reliability have often led to the belief that 60 kHz signals propagate great distances over ground wave paths alone. In reality, a combination of surface wave and D-layer ionospheric paths are responsible for WWVB signal propagation. At night, cosmic background radiation supports a level of D-layer ionization that is sufficient for propagating LF (and lower frequency) radio signals over long distances. Greater D-layer efficiencies and increased effective height with decreased ionization levels contribute to greater signal coverage during the nighttime hours. etc... So, here we have propagation via the ionospheric D-Layer which I believe is considered a skywave. Note that the author talks about measuring broadcast band frequencies to an accuracy 312 micro-hertz, where such things as varying path lengths are important. The wavelength of 60 KHz is about 5 km. The height of the D layer varies from 60 to 90 km or about 12 to 18 wavelengths at 60 KHz. That's too big for a waveguide structure, which suggests that the dominant mode of propagation is skywave, not ground wave. There is no frequency at which ground wave ceases and skywave takes over. There seems to be quite a bit of overlap. Mo https://en.wikipedia.org/wiki/Very_low_frequency#Propagation_characteristics -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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