|
4NEC2?
Whereas such antenna predictors seem to feature in amateur usage,
does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? |
4NEC2?
"Gareth's Downstairs Computer" wrote in message ... Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? you will only need a cellphone antenna to enjoy amateur radio in the future ..... |
4NEC2?
Rambo wrote:
Gareth's Downstairs Computer headstone255.but.n Wrote in message: Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? G is for Gentleman R is for rimjob. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
Gareth's Downstairs Computer
wrote: Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? G is for genital warts. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
Brian Morrison wrote:
On Sat, 13 Oct 2018 09:33:55 +0100 Gareth's Downstairs Computer wrote: Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? I currently have a build of openEMS going on my Fedora system, once it's built and installed I shall have a play and see what I can glean from it. Yes, I understand the underlying principles of antennas, Burt thought he did, too. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
On Sat, 13 Oct 2018 09:33:55 +0100, Gareth's Downstairs Computer
wrote: Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? I understand how antenna work and how to predict performance. I can even do it without 4NEC2 or other antenna modeling program. For example, the uglier the antenna, the better it works. Antennas that are more expensive, bigger, and in violation of local building ordinances, work the best. Experimental prototype antennas always work while the production versions never seem to work as well. If there are two ways to assemble an antenna, the wrong way will have higher gain, lower VSWR, or both. High gain, small size, or wide bandwidth; pick any two. Using these rules of thumb and others, anyone can predict how well an antenna will perform by inspection and without using computer models, Smith charts, or tedious calculations. As for your inability to distinguish yourself from consumerist CBers and beginning licensees, it might be because you have most of the characteristics of both. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
Jeff Liebermann wrote:
On Sat, 13 Oct 2018 09:33:55 +0100, Gareth's Downstairs Computer wrote: Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? I understand how antenna work and how to predict performance. I can even do it without 4NEC2 or other antenna modeling program. For example, the uglier the antenna, the better it works. Antennas that are more expensive, bigger, and in violation of local building ordinances, work the best. Experimental prototype antennas always work while the production versions never seem to work as well. If there are two ways to assemble an antenna, the wrong way will have higher gain, lower VSWR, or both. High gain, small size, or wide bandwidth; pick any two. Using these rules of thumb and others, anyone can predict how well an antenna will perform by inspection and without using computer models, Smith charts, or tedious calculations. As for your inability to distinguish yourself from consumerist CBers and beginning licensees, it might be because you have most of the characteristics of both. Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
On 13 Oct 2018 20:53:13 GMT, Stephen Thomas Cole
wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). About two months ago, one of my friends was complaining that the range of his VHF/UHF mobile was severely limited. He decided that he must have blown up his radio. I did a bench test of the radio and it was fine. That left the vehicle power system, power cord, coax cable, and antenna as the remaining potential suspects. I inspected the electrical system and found that fuse on the negative lead had blown. Why manufacturers persist in providing a negative wire fuse will remain a mystery as there are very few positive ground vehicles still in service and even marine radios with floating grounds are scarce. I have no idea where the radio was getting its ground return for reasons that will soon be obvious. I replaced the fuse and continued looking for problems. Next came the coax and antenna system. I have a nifty little gadget I built that has been very handy for troubleshooting mobile installs. It's an NMO antenna "connector" to UHF adapter. https://www.americanradiosupply.com/opek-nmo-8-nmo-antenna-connector-to-uhf-female-so-239-adapter/ I remove the NMO antenna, screw this adapter onto the NMO mount, and check for RF power. In this case, no RF as in zero, zilch, none, no RF. However, at the radio end, there was 45 watts of VHF RF. So, the coax must be the problem. Fast forward an hour of fruitless testing and I'm still not seeing any RF. Eventually, I run a simple ohmmeter continuity test between the ends of the coax cable and find that it's open circuit. Huh? Unless something has cut the cable (we have a local mouse problem), even a defective coax cable will show end to end continuity. I trace out the coax cable only to find two identical cables running in parallel. That wasted another hour because all the multiple radio cables were behind a workbench and a pile of junk in the van. One coax cable had the RF connector at the radio end and nothing at the other end. The other cable had the NMO connector on one end, and nothing on the other end. I should have guessed but I had assumed that the owner had done a VSWR test during the initial coax cable installation. Apparently, it had been like that for several weeks before the owner noticed that his VHF/UHF coverage was lacking. Since he lives just below the local repeaters, that's somewhat understandable. So, if anyone asks if they really need an antenna, tell them no. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
Jeff Liebermann wrote:
On 13 Oct 2018 20:53:13 GMT, Stephen Thomas Cole wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). About two months ago, one of my friends was complaining that the range of his VHF/UHF mobile was severely limited. He decided that he must have blown up his radio. I did a bench test of the radio and it was fine. That left the vehicle power system, power cord, coax cable, and antenna as the remaining potential suspects. I inspected the electrical system and found that fuse on the negative lead had blown. Why manufacturers persist in providing a negative wire fuse will remain a mystery as there are very few positive ground vehicles still in service and even marine radios with floating grounds are scarce. I have no idea where the radio was getting its ground return for reasons that will soon be obvious. I replaced the fuse and continued looking for problems. Next came the coax and antenna system. I have a nifty little gadget I built that has been very handy for troubleshooting mobile installs. It's an NMO antenna "connector" to UHF adapter. https://www.americanradiosupply.com/opek-nmo-8-nmo-antenna-connector-to-uhf-female-so-239-adapter/ I remove the NMO antenna, screw this adapter onto the NMO mount, and check for RF power. In this case, no RF as in zero, zilch, none, no RF. However, at the radio end, there was 45 watts of VHF RF. So, the coax must be the problem. Fast forward an hour of fruitless testing and I'm still not seeing any RF. Eventually, I run a simple ohmmeter continuity test between the ends of the coax cable and find that it's open circuit. Huh? Unless something has cut the cable (we have a local mouse problem), even a defective coax cable will show end to end continuity. I trace out the coax cable only to find two identical cables running in parallel. That wasted another hour because all the multiple radio cables were behind a workbench and a pile of junk in the van. One coax cable had the RF connector at the radio end and nothing at the other end. The other cable had the NMO connector on one end, and nothing on the other end. I should have guessed but I had assumed that the owner had done a VSWR test during the initial coax cable installation. Apparently, it had been like that for several weeks before the owner noticed that his VHF/UHF coverage was lacking. Since he lives just below the local repeaters, that's somewhat understandable. So, if anyone asks if they really need an antenna, tell them no. LOL! That’s a great story, cheers! :-D -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
"Jeff Liebermann" wrote in message ... On 13 Oct 2018 20:53:13 GMT, Stephen Thomas Cole wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn't reach further than a quarter mile. That's all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). About two months ago, one of my friends was complaining that the range of his VHF/UHF mobile was severely limited. He decided that he must have blown up his radio. I did a bench test of the radio and it was fine. That left the vehicle power system, power cord, coax cable, and antenna as the remaining potential suspects. I inspected the electrical system and found that fuse on the negative lead had blown. Why manufacturers persist in providing a negative wire fuse will remain a mystery as there are very few positive ground vehicles still in service and even marine radios with floating grounds are scarce. I have no idea where the radio was getting its ground return for reasons that will soon be obvious. I replaced the fuse and continued looking for problems. Next came the coax and antenna system. I have a nifty little gadget I built that has been very handy for troubleshooting mobile installs. It's an NMO antenna "connector" to UHF adapter. https://www.americanradiosupply.com/opek-nmo-8-nmo-antenna-connector-to-uhf-female-so-239-adapter/ I remove the NMO antenna, screw this adapter onto the NMO mount, and check for RF power. In this case, no RF as in zero, zilch, none, no RF. However, at the radio end, there was 45 watts of VHF RF. So, the coax must be the problem. Fast forward an hour of fruitless testing and I'm still not seeing any RF. Eventually, I run a simple ohmmeter continuity test between the ends of the coax cable and find that it's open circuit. Huh? Unless something has cut the cable (we have a local mouse problem), even a defective coax cable will show end to end continuity. I trace out the coax cable only to find two identical cables running in parallel. That wasted another hour because all the multiple radio cables were behind a workbench and a pile of junk in the van. One coax cable had the RF connector at the radio end and nothing at the other end. The other cable had the NMO connector on one end, and nothing on the other end. I should have guessed but I had assumed that the owner had done a VSWR test during the initial coax cable installation. Apparently, it had been like that for several weeks before the owner noticed that his VHF/UHF coverage was lacking. Since he lives just below the local repeaters, that's somewhat understandable. So, if anyone asks if they really need an antenna, tell them no. no idea why but that reminds me of a car I had that lost the engine earth and it earthed through the accelerator cable which overheated and caused a lot of smoke...just thought I would throw that in ....no idea why |
4NEC2?
On 13/10/2018 20:43, Jeff Liebermann wrote:
I understand how antenna work and how to predict performance. I can even do it without 4NEC2 or other antenna modeling program. For example, the uglier the antenna, the better it works. Antennas that are more expensive, bigger, and in violation of local building ordinances, work the best. Experimental prototype antennas always work while the production versions never seem to work as well. If there are two ways to assemble an antenna, the wrong way will have higher gain, lower VSWR, or both. High gain, small size, or wide bandwidth; pick any two. Using these rules of thumb and others, anyone can predict how well an antenna will perform by inspection and without using computer models, Smith charts, or tedious calculations. WHS There has been much talk on UKRA in the recent past about the merits or otherwise of various makes and models of VNAs. It's my view that the point of having an Amateur licence is to be able to transmit signals intended to be received by another station. One of the alleged virtues of a VNA is to be able to set up one's aerial system. However, I maintain that using cheap torch bulbs is an equally valid indicator of the state of tune of one's station, and that a distant station cannot tell the difference between a system set up with the aid of a VNA and one set up with the aid of a torch bulb or two. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On 14/10/2018 01:32, Jeff Liebermann wrote:
wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That’s all you need to know about him and and his ability with radio. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Sun, 14 Oct 2018 08:50:13 +0000
Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That’s all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? |
4NEC2?
Geoff wrote:
On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn't reach further than a quarter mile. That's all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? I hope I am as open-minded as the next person, but it is really stretching credulity to accept that anyone could actually find that alleged fact remotely interesting. -- Roger Hayter |
4NEC2?
"Spike" wrote in message ... On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn't reach further than a quarter mile. That's all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. even I know that one ..... |
4NEC2?
"Jeff" wrote in message ... I inspected the electrical system and found that fuse on the negative lead had blown. Why manufacturers persist in providing a negative wire fuse will remain a mystery as there are very few positive ground vehicles still in service and even marine radios with floating grounds are scarce. I have no idea where the radio was getting its ground return for reasons that will soon be obvious. I replaced the fuse and continued looking for problems. The negative fuse is nothing to do with positive ground vehicles (and a radio with the case connected to negative would not work in a positive ground vehicle anyway without additional isolation). I wired up a neg ground rev counter to my pos earth 1963 mini in 1969 by insulating the live case of the rev counter and earthing the live terminal...worked well ..... |
4NEC2?
On 14/10/2018 11:04, Geoff wrote:
On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That’s all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On 14/10/2018 11:18, Roger Hayter wrote:
Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn't reach further than a quarter mile. That's all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? I hope I am as open-minded as the next person, but it is really stretching credulity to accept that anyone could actually find that alleged fact remotely interesting. It's only interesting as in its showing how any stick can be useful to a person of a particular mind-set to beat a dog, as it were, even if the beater can be then be beaten in turn with a similar stick, raising the question of why the mind-set of the original beater impels him to do this self-destructive act repeatedly. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Sun, 14 Oct 2018 11:39:58 +0000
Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That’s all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. |
4NEC2?
On 14/10/2018 11:44, Geoff wrote:
On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Sun, 14 Oct 2018 11:55:13 +0000
Spike wrote: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. |
4NEC2?
On Sun, 14 Oct 2018 11:55:13 +0000
Spike wrote: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. Burt, what was it you were saying about being beaten with your own schtick, Burt? Burt, T H A N K S, Burt. |
4NEC2?
On 14/10/2018 11:57, Geoff wrote:
On Sun, 14 Oct 2018 11:55:13 +0000 Spike wrote: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. That's not an issue, after all, life is about choices - some people make poor choices and never progress at all in any Class of UK licence that they have held. I choose to take that as a sign of their low self-esteem - as I do about people deleting, or choosing not to archive, posts of theirs that shown them in a poor light. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Sun, 14 Oct 2018 12:27:44 +0000
Spike wrote: On 14/10/2018 11:57, Geoff wrote: On Sun, 14 Oct 2018 11:55:13 +0000 Spike wrote: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. That's not an issue, after all, life is about choices - some people make poor choices and never progress at all in any Class of UK licence that they have held. I choose to take that as a sign of their low self-esteem - as I do about people deleting, or choosing not to archive, posts of theirs that shown them in a poor light. There are also people who just make things up, to serve their own petty spitefulness. I choose not to believe a word those people say. |
4NEC2?
On Sun, 14 Oct 2018 12:27:44 +0000, Spike
wrote: That's not an issue, after all, life is about choices - some people make poor choices and never progress at all in any Class of UK licence that they have held. Define "progress", bearing in mind that the primary purpose of an amateur licence was "self training", not "working CW on 20". I choose to take that as a sign of their low self-esteem Spare us the cod psychology. |
4NEC2?
Spike wrote:
On 14/10/2018 11:18, Roger Hayter wrote: Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn't reach further than a quarter mile. That's all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? I hope I am as open-minded as the next person, but it is really stretching credulity to accept that anyone could actually find that alleged fact remotely interesting. It's only interesting as in its showing how any stick can be useful to a person of a particular mind-set to beat a dog, as it were, even if the beater can be then be beaten in turn with a similar stick, raising the question of why the mind-set of the original beater impels him to do this self-destructive act repeatedly. Ah, the 'he started it' argument, familiar to any parent. -- Roger Hayter |
4NEC2?
On 14/10/2018 15:08, Roger Hayter wrote:
Spike wrote: On 14/10/2018 11:18, Roger Hayter wrote: Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn't reach further than a quarter mile. That's all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? I hope I am as open-minded as the next person, but it is really stretching credulity to accept that anyone could actually find that alleged fact remotely interesting. It's only interesting as in its showing how any stick can be useful to a person of a particular mind-set to beat a dog, as it were, even if the beater can be then be beaten in turn with a similar stick, raising the question of why the mind-set of the original beater impels him to do this self-destructive act repeatedly. Ah, the 'he started it' argument, familiar to any parent. You've obviously read "....even if the beater can be then be beaten..." as a mandatory response that the beater will necessarily be beaten in turn. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Sun, 14 Oct 2018 05:59:35 -0700 (PDT)
Jeefaw K Effkay wrote: On Sunday, October 14, 2018 at 12:57:21 PM UTC+1, Geoff wrote: On Sun, 14 Oct 2018 11:55:13 +0000 Spite sent a message from the other side: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spite sent a message from the other side: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike lied: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. What STC actually asked was which sideband he should use for RTTY on 40m. Which is, of course, an interesting question as it's not something that was covered in any exam, current or previous. My $0.02 worth is that it doesn't matter, since an RTTY operator will know that he needs to invert the received tones if he sees a string of "46464646" instead of "RYRYRYRY" Here's what was asked, and it wasn't posted no archive, or deleted, or any of the other weak bull**** that Burt has bean spraying around: "Was pottering at my radio last night, heard the scream of data being sent and was triggered to revisit a long parked project; getting going on RTTY! Here's the hardware I'm using: Yaesu FT757-GXii Serial/USB cable interface thing PowerMac G4 running CocoaModem I've got everything hooked up, have CocoaModem configured and displaying a waterfall but when set to RTTY mode it's just decoding gibberish... Other than a couple of short spells at club days, this is my first go at this and I have no idea what I'm doing... Any tips?" https://groups.google.com/forum/#!or...A/_ityI76x0IMJ Good old Burt. |
4NEC2?
On 14/10/2018 09:49, Spike wrote:
On 13/10/2018 20:43, Jeff Liebermann wrote: I understand how antenna work and how to predict performance. I can even do it without 4NEC2 or other antenna modeling program. For example, the uglier the antenna, the better it works. Antennas that are more expensive, bigger, and in violation of local building ordinances, work the best. Experimental prototype antennas always work while the production versions never seem to work as well. If there are two ways to assemble an antenna, the wrong way will have higher gain, lower VSWR, or both. High gain, small size, or wide bandwidth; pick any two. Using these rules of thumb and others, anyone can predict how well an antenna will perform by inspection and without using computer models, Smith charts, or tedious calculations. WHS There has been much talk on UKRA in the recent past about the merits or otherwise of various makes and models of VNAs. It's my view that the point of having an Amateur licence is to be able to transmit signals intended to be received by another station. One of the alleged virtues of a VNA is to be able to set up one's aerial system. However, I maintain that using cheap torch bulbs is an equally valid indicator of the state of tune of one's station, and that a distant station cannot tell the difference between a system set up with the aid of a VNA and one set up with the aid of a torch bulb or two. The PP seems unaware of retarded potentials, and has blustered his way by responding to the question without actually any understanding of the issues involved. |
4NEC2?
On Sun, 14 Oct 2018 10:26:55 +0100, Jeff wrote:
I inspected the electrical system and found that fuse on the negative lead had blown. Why manufacturers persist in providing a negative wire fuse will remain a mystery as there are very few positive ground vehicles still in service and even marine radios with floating grounds are scarce. I have no idea where the radio was getting its ground return for reasons that will soon be obvious. I replaced the fuse and continued looking for problems. The negative fuse is nothing to do with positive ground vehicles (and a radio with the case connected to negative would not work in a positive ground vehicle anyway without additional isolation). The negative fuse is there to stop high currents, such as the starter motor, being drawn through the radio wiring and coax should the battery to chassis connection be high resistance or open circuit, and prevent a possible fire. This is at greatest risk if the radio negative is wired directly to the battery. Jeff That seems reasonable. However, I've never seen that happen. More common was blowing or removing the negative power cable fuse to the radio. That makes the DC ground return for the radio go through either the car frame, which will produce alternator noise on the transmit signal, or through the coax cable, which will produce a smoking coax cable in transmit. I've seen both about 5 times each in the last 50 years. I would consider these faults to be a greater risk than a disconnected battery to chassis (or engine) ground cable. "Wiring and Grounding" http://www.k0bg.com/wiring.html And as shown, the negative lead fuse should not be removed. The reason is, if the grounding point should lose its integrity, excessive current could flow through the transceiver's negative lead. It also prevents a minor ground loop between the leads. Most vehicles have a ground strap between the engine block and frame and another ground cable between the frame and negative battery terminal. I sometimes see a third cable from battery to engine block. In this arrangement, any one of the three wires could be disconnected and one would still have a tolerable grounding system. Fiberglass body automobiles have duplicate ground wiring since there is no frame ground. "How To Properly Ground An Automotive Electrical System" https://www.hotrodwires.com/how-to-ground-automotive-electrical-system.html "Is it necessary to have two ground wires (1 to engine and 1 to" car-frame)? https://mechanics.stackexchange.com/questions/5903/is-it-necessary-to-have-two-ground-wires-1-to-engine-and-1-to-car-frame -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
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4NEC2?
In article ,
says... What STC actually asked was which sideband he should use for RTTY on 40m. Which is, of course, an interesting question as it's not something that was covered in any exam, current or previous. My $0.02 worth is that it doesn't matter, since an RTTY operator will know that he needs to invert the received tones if he sees a string of "46464646" instead of "RYRYRYRY" Here's what was asked, and it wasn't posted no archive, or deleted, or any of the other weak bull**** that Burt has bean spraying around: "Was pottering at my radio last night, heard the scream of data being sent and was triggered to revisit a long parked project; getting going on RTTY! Here's the hardware I'm using: Yaesu FT757-GXii Serial/USB cable interface thing PowerMac G4 running CocoaModem I've got everything hooked up, have CocoaModem configured and displaying a waterfall but when set to RTTY mode it's just decoding gibberish... Other than a couple of short spells at club days, this is my first go at this and I have no idea what I'm doing... Any tips?" https://groups.google.com/forum/#!or...A/_ityI76x0IMJ Good old Burt. If the wrong sideband or inversion of the tones is the problem, it will not be a string of 4646 instead of RYRY. They are both the same except the printer is shifted for the 4646. What will hapen is that instead of RYRY it will be YRYR but all the other characters will be scrambled. It does not matter what sideband is used for RTTY if the tones are inverted. However in most normal ham RTTY lower side band is used for receiving and if audio tones are fed into the audio for transmitting. This makes the tones come out the same when used on AM or FM on VHF. For HF it does not even matter what the frequency of the audio tones are if they are the usual 170 Hz difference as long as they pass through the audio of the transmitter and receiver. Usually 2125 and 2295 are used as this is about as high as will pass the audio and if running a ssb transmitter the 2 nd and higher harmonics are filtered out to some extent if need be by the transmitter filter. |
4NEC2?
On Sun, 14 Oct 2018 08:50:13 +0000, Spike
wrote: Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That’s all you need to know about him and and his ability with radio. For what it's worth, I don't know which sideband to use on 40m. That's because I don't operate much on 40m and don't have such details memorized. I use a wall chart with the appropriate modes, frequencies, sub-bands, and dedicated frequencies listed. Oddly, I was able to pass the US extra-class license without knowing or studying any of this. I believe I posted the story previously, but it's interesting enough to repeat again. I don't recall what year, but at the time, the FCC decided to drop the US Morse Code requirements. Since the technician class license consisted of the exact same technical questions as the general class license (element 3), it was decided that one could upgrade from technician to general without taking any additional tests and by simply paying a nominal processing fee. I arrived at the scheduled VEC exam session and presented my collection of expired licenses and forms as proof that I passed the technician class exam. Since I didn't need to pass an exam, I hadn't studied. I was then informed that I could take the extra class exam (element 4). If I failed, I would still get the general class license. Seemed like a reasonable thing to do. So, I took the extra class exam, totally and completely unprepared. I didn't even bring a calculator. Except for some creative wording in many of the questions, the technical parts were quite familiar and easy. However, element 4 also included some questions that required operating experience, such as band edges for the extra class only sub-bands, and similar questions. I did my best by guessing and was certain that I had failed the exam. Amazingly, I passed. So, if anyone asks if it is possible to pass the US extra class exam without knowing much about HF operating standards, I would answer that it might be possible. From my warped perspective, the ham license is NOT a demonstration of competence. It's simply the minimum one is expected to know so that they can operate a ham transmitter without breaking any rules, becoming a nuisance, or otherwise making a mess of the frequencies. One learns ham radio AFTER obtaining a license, not before. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On Sun, 14 Oct 2018 08:49:51 +0000, Spike
wrote: On 13/10/2018 20:43, Jeff Liebermann wrote: I understand how antenna work and how to predict performance. I can even do it without 4NEC2 or other antenna modeling program. For example, the uglier the antenna, the better it works. Antennas that are more expensive, bigger, and in violation of local building ordinances, work the best. Experimental prototype antennas always work while the production versions never seem to work as well. If there are two ways to assemble an antenna, the wrong way will have higher gain, lower VSWR, or both. High gain, small size, or wide bandwidth; pick any two. Using these rules of thumb and others, anyone can predict how well an antenna will perform by inspection and without using computer models, Smith charts, or tedious calculations. WHS Thou shalt not abrev. What does WHS mean? There has been much talk on UKRA in the recent past about the merits or otherwise of various makes and models of VNAs. It's my view that the point of having an Amateur licence is to be able to transmit signals intended to be received by another station. One of the alleged virtues of a VNA is to be able to set up one's aerial system. However, I maintain that using cheap torch bulbs is an equally valid indicator of the state of tune of one's station, and that a distant station cannot tell the difference between a system set up with the aid of a VNA and one set up with the aid of a torch bulb or two. In a past life (1970's), I used to design marine radios and antennas. At the time, my weapon of choice was the HP4815A vector impedance meter: https://www.google.com/search?q=hp4815a&tbm=isch No fancy display, no pretty graphs, no Smith chart display. Just accurate numbers for the HF bands. I used it for everything that needed impedance matching, including antennas. If you're thinking of buying one, make sure that it includes the probe kit. It's useless without the probe kit. http://electropuces.pagesperso-orange.fr/Photos/HP4193.jpg One of my ace technicians had a different way of doing RF. During the day, he would use the best test equipment that the company could afford. After hours, he would work on his own radios. However, instead of using proper test equipment, he would literally tune for maximum into a light bulb. I was disgusted, tried to help, but failed. He insisted that a light bulb was "good enough". It took me a while to decode what was happening. Anyone can produce a workable antenna using primitive techniques. By workable, I mean minimally functional and generally usable. For at time, I was building matching networks for using an aluminum step ladder as a VHF directional antenna. It worked, but improvements beyond minimally functional were difficult. So, why bother with all the fancy test equipment (VNA) if a light bulb will do as well? Because with the fancy test equipment will squeeze the last few decibels of performance out the antenna while the light bulb is unlikely to do the same. If minimally acceptable is your standard of excellence, then please continue using a light bulb for tuning antennas. However, if you want to get all the performance possible, then you'll need some fancy test equipment. What was happening with my tech was that he did not want to expend the time learning how to properly operate, understand, and analyze the output from the fancy test equipment. While I consider this close to sacrilege in a production environment, to someone just trying to get his radio or antenna on the air, it's sufficient. If I light bulb got him close enough to a working system, and didn't require any time to study, it was "good enough". Some of the local hams are very much into DX, contesting, and EME. To be successful, one has to have a very efficient radio system with everything optimized to the best possible performance. Everything has to be optimized for the best possible performance. One can't do that with a light bulb. Since your view of ham radio is "to be able to transmit signals intended to be received by another station", you don't need a VNA to do that. An antenna tuner and a random length of wire will suffice. However, if you plan to do more than that, some test equipment might be useful. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On Sun, 14 Oct 2018 18:50:34 +0100, Brian Morrison
wrote: On Sun, 14 Oct 2018 10:42:24 -0700 Jeff Liebermann wrote: For what it's worth, I don't know which sideband to use on 40m. For data modes it's just about all USB, and has been for some time. But it's easy to see why people can get confused and wonder what they set up incorrectly. No need to beat anyone up about it, just explain if you're asked. I don't think I'm beating up on anyone, but if an explanation is required, I can do that. It might help to understand why some bands use LSB while others USB. In the early daze of sideband radio, the common IF frequency was 9MHz. The radios had only one sideband filter. With one filter, it was cheaper and easier to mix and up convert in the transmitter. So, to save the cost of adding a second filter, the bands below 9MHz were designated as LSB and the band above 9MHz became USB. Eventually, radios were built with two sideband filters, and this was no longer important. As usual, the legacy technology remained in place to haunt the survivors to this day. The problem repeated itself with the rise of the digital modes. People wanted mult-band radios, but didn't want two filters in the radio. So, someone flipped a coin and decided that everything should be USB when using digital modes. For example, with JT65A, it's USB on all bands: http://hflink.com/jt65/ I'm not quite sure if that's also the case with other digital modes. For example, PSK31 (BPSK) doesn't care if you use USB or LSB, but by convention, USB is preferred. For marine radio HF communications, it's all USB. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On Sun, 14 Oct 2018 13:39:38 -0400, Ralph Mowery
wrote: I don't know anything about the tractor trailer wiring, but around 1972 I picked up extra money repairing the CB radios. Several truckers brought in rigs that were blown up when switching from the car to the truck. None of them had a fuse in the negative power lead. By blown up, most had a diode across the poer wires inside the transceiver and that diode had shorted and blew the fuse. I seem to remember then they talked about the tractor haveing a positive ground. Probably ran on 24 volts also. I installed a few radios in White Freightliner tractors in the 1960's. They were all positive ground 12V. I think they switch to negative ground in about 1975. Many other older tractors were positive ground but switched to negative ground in about 1954-56. I vaguely recall conversion kits being sold at the time. I've seen a few 24V electrical systems, but those were all in military vehicles. I have only ran FM ham rigs in a car. I used to ground the rig to the frame and run the positive to a relay that comes on when the car is started. Never had any alternator whine or problems. For about the last 10 or more years I just plug into the lighter or accessory socket in the car. My Toyota power on those sockets only come on when the car is started. You might want to put a voltmeter across the power connector going to your radio and across the battery, and compare voltages in transmit. Methinks you'll find a rather substantial voltage drop through the cigarette igniter jack. Also, that connector was never designed to handle a plug and jack connector arrangement. It's the only connector that I know of that has a spring which pushed the plug OUT of the jack and lacks a retention system. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
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4NEC2?
In message , Bernie
writes On Sun, 14 Oct 2018 05:59:35 -0700 (PDT) Jeefaw K Effkay wrote: On Sunday, October 14, 2018 at 12:57:21 PM UTC+1, Geoff wrote: On Sun, 14 Oct 2018 11:55:13 +0000 Spite sent a message from the other side: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spite sent a message from the other side: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike lied: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. What STC actually asked was which sideband he should use for RTTY on 40m. Which is, of course, an interesting question as it's not something that was covered in any exam, current or previous. My $0.02 worth is that it doesn't matter, since an RTTY operator will know that he needs to invert the received tones if he sees a string of "46464646" instead of "RYRYRYRY" Here's what was asked, and it wasn't posted no archive, or deleted, or any of the other weak bull**** that Burt has bean spraying around: "Was pottering at my radio last night, heard the scream of data being sent and was triggered to revisit a long parked project; getting going on RTTY! Here's the hardware I'm using: Yaesu FT757-GXii Serial/USB cable interface thing PowerMac G4 running CocoaModem I've got everything hooked up, have CocoaModem configured and displaying a waterfall but when set to RTTY mode it's just decoding gibberish... Other than a couple of short spells at club days, this is my first go at this and I have no idea what I'm doing... Any tips?" https://groups.google.com/forum/#!or...-radio/MjriIIU zuHA/_ityI76x0IMJ Good old Burt. For the record all the data modes including RTTY use upper sideband all the way up from 136KHz . CW A1A is also upper sideband but there can be advantages to be had by swapping to LSB to avoid interference. F1A beacons seem to be a law unto themselves. You can get quite good at reading inverted morse. Amateur RTTY uses inverted tones and a different narrower shift compared with commercial RTTY. I don't know why your getting onto Steve about this as none of it is the radio amateur courses or even online anywhere, unless some smarty pants comes along and tells me it is. Ok it's in here for WSJT https://physics.princeton.edu/pulsar/k1jt/doc/wsjt/ "Turn on your radio, select USB (or USB Data) mode, and tune to a clear frequency so that only background noise is sent to the sound card" Brian -- Brian Howie |
4NEC2?
In message , Gareth's Downstairs Computer
writes Whereas such antenna predictors seem to feature in amateur usage, does anyone, anywhere, in the world of amateur radio have an understanding of the underlying principles involved in predicting the performance of antennae, or have we all, regrettably, become indistinguishable from consumerist CBers or beginner licensees? 4NEC2 and EZNEC are just a fancy front and back ends for NEC2 (and NEC4) Engines. Program description is here :- https://ntrl.ntis.gov/NTRL/dashboard...tail/ADA956129. xhtml. "Part I of the document includes the equations on which the code is based and a discussion of the approximations and numerical methods used in the numerical solution. Some comparisons to demonstrate the range of accuracy of approximations are also included. Details of the coding and a User's Guide are provided as parts 11 and 111, respectively." It's pretty straight forward stuff for someone good (1st year uni) at maths*. The rest of us just have to take their word for it. The code is written in good old FORTRAN, so I can at least follow the code. *It's USAnian maths. Which is a different dialect to British maths. Brian -- Brian Howie |
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