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Relationship Between Antenna Efficiency and Received Signal Strength
On Fri, 24 Jan 2014 20:29:22 -0500, Jerry Stuckle
wrote: Receiver sensitivity was 0.2 mv for 20db S+N/N ratio. I'll assume that you mean 0.2 microvolts, not millivolts. Also, nobody has uses 20dB S+N/N since about the 1960's except maybe the ARRL[1]. 12dB SINAD has been around since about the mid 1960's. http://en.wikipedia.org/wiki/SINAD I don't know how much better; the surplus signal generator I was using wasn't that accurate. At the time, I used a Gertsch FM-something. It's the box with only the left handle showing at the extreme right of the pictu http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html It wasn't every accurate, and not really intended to be used as a signal source. However, I had a precision step attenuator, and since the Gertsch factory was near my parents house, it wasn't too difficult to get it calibrated in trade for some grunt work. And BTW - 'm' can also mean micro, especially when you don't have a Greek alphabet available. 'u' is not the same as the Greek 'mu' and can be confusing. Of course, using 'm' for both milli and micro can be confusing, unless you know the context. If you follow SI standards, the "m" means milli. http://physics.nist.gov/cuu/Units/prefixes.html If you have a PC keyboard, try using the key combination: alt0181 on the number pad which produces a µ symbol. http://symbolcodes.tlt.psu.edu/accents/codealt.html [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. I suppose there might be some dinosaurs roaming the earth still talking about "20 dB quieting". -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
On Fri, 24 Jan 2014 20:25:42 -0500, Jerry Stuckle
wrote: On 1/24/2014 7:14 PM, Jeff Liebermann wrote: On Fri, 24 Jan 2014 13:04:48 -0500, Jerry Stuckle wrote: The easiest way of seeing it is looking at the output of both tube and transistorized transmitters on a spectrum analyzer. You will see much more hash on the transistorized transmitter. Amazing. You might see more hash with a synthesized transistor xmitter, but for crystal controlled, they noise is quite a bit less with transistors. You obviously don't use a decent spectrum analyzer. I've never seen or used an indecent spectrum analyzer. These are admittedly antiques, but do a tolerable job for most things I need: http://802.11junk.com/jeffl/pics/home/slides/test-equip-mess.html I wouldn't mind owning a much better spectrum analyzer, but I can't justify the expense. If I need one, I can usually borrow, or if really desperate, rent. Sure - WITH DUPLEXERS. I did it WITHOUT DUPLEXERS. A HUGE difference. But obviously one YOU DON'T UNDERSTAND. Do you even know what a duplexer is? (I really doubt it). I've been fairly polite up until now. I've tried to correct your mistakes, but have never stooped to personal insults and accusations. You don't seem to know how to engage in a technical discussion without being insulting. No more nice guy. I've designed two 900 MHz commercial duplexers used in wireless SCADA systems. I've tuned probably around 50 assorted duplexers for a mixture of ham and commercial users. My only failure was when a local ham machined a rather nice looking duplexer out of 6" stove pipe, and then wondered why it didn't work as well as the silver plated variety. In my spare time, I'm trying to improve on the bad joke of a duplexer found in the Motorola MSF5000 UHF repeater. http://802.11junk.com/jeffl/K6BJ-MSF5000/ Yes, I think I know what a duplexer is. Yes, nowadays, there are transistors with lower noise figures. But they are relatively expensive, and you won't find them in the less expensive receivers. Rubbish. pHEMT devices are available with 0.75dB NF at 1GHz for under $3/ea. For example: http://www.minicircuits.com/pdfs/PSA4-5043+.pdf Note that this isn't just a single device but a MMIC amplifier capable of belching 100 mw (+20dBm) with 1dB gain compression. Which you don't use in the front end of a receiver. But I see you don't understand anything that's been said in this thread, so no surprise there. Actually, you do, but I picked an example that could be used in a transmit chain, which I believe was the topic of discussion. No, AGC will not "try to keep the S/N ratio constant". It tries to keep the output of the IF constant. As the signal increases, the noise will decrease, improving the S/N ratio. But you also don't seem to understand how AGC works. I stand corrected. The rest of what I said about AGC is correct. Even back in the early 70's, commercial tube VHF radios could easily get .15mv for 20db S+N/N ratio. Not much different than the transistorized versions today. I think you might mean 0.15 uv/12dB SINAD. A 0.15mv receiver would be considere comatose. No, I mean 20db S+N/N ratio. The equivalent SINAD would be somewhere around .12mv (or a bit less). Not at all "comatose". Please fix your abrevs. http://physics.nist.gov/cuu/Units/prefixes.html I never saw any tube receivers with 0.12µV/12dB SINAD sensitivity. However, that was at UHF. I don't recall the numbers I was getting for VHF and low band tube receivers. I could probably excavate some old Motorola Research line manuals and see what Motorola specifies in the manual. That must be because you were working on GE Pre-Prog. I worked with both Motorola and RCA sets (plus a few others which weren't quite as good). We were able to get them to .15mv. on VHF. The radios in the repeater rack are all Progress Line, not Pre-Prog. No experience with RCA, but the Motorola 5V, 40V, 80D and 140D were much the same as the Progress line radios. The UHF (T44) versions started out at about 0.5µV/12dB SINAD and slowly deteriorated to about 1µV. VHF receivers were somewhat better than that, but I don't recall the numbers. But then according to you, such a radio would be "comatose". I wonder just how bad your GE's were? The comatose was in reference to your abuse of the SI prefixes. 1mv/12DB SINAD is terrible. Such a receiver would never have left our shop. Please fix your abrevs. http://physics.nist.gov/cuu/Units/prefixes.html 0.5mv wouldn't leave our shop, either. Please fix your abrevs. http://physics.nist.gov/cuu/Units/prefixes.html And both Motorola and RCA rigs would hold their sensitivity for much longer than that, even in a mobile installment. It was worse in repeater service, where we had to cram 3 repeaters in a rack because of limited floor space. Note the big squirrel cage blowers on the bottom of the rack. http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/Santiago-01.html Mobiles had to be retuned about once a year to maintain optimum performance. TX output tubes would last about 3 years. (6907 for GE and 2C39 for Motorola). Somewhat later, in the 1970's, I found myself designing marine radios. Typical VHF sensitivity was about 0.25uv/12dB SINAD using a dual gate MOSFET front end such as a 40673 or 3N212. We ocassionally used JFET's such as a U310 but the sensitivity was about the same. Yea, one of the shops I worked at sold similar quality rigs, mainly for those who wouldn't pay for a good RCA. The Motorola shop didn't sell anything else, of course. Interesting. I mention the front end devices and you immediately deduce everything about the product, the quality, and maybe even are able to guess the manufacturer? Wanna take a guess? You can even Google for the right answer without much difficulty. We were making marine radios in the USA for about 15 years. It wasn't the lack of quality that eventually killed the company. It was competition initially from Japan and later from China. Of course, you must prefer the current level of quality from China. Maybe in your designs, but not in the ones most of our clients demanded and paid for. You designed radios? Good to know. Our radios were used by the USCG, tug boats, inland waterways barges, bridges, and cruise ships. Those types of customers don't tolerate failures very gracefully. We also offered a lifetime warranty to underscore the point. Resurrecting 10 year old radios was not fun, but that's what it took to stay in business. Incidentally, my best day was when I visited the USCG repair depot on Yerba Buena Island, and saw a rather large pile of Motorola Modar radios. When I asked, I was told those were the one's they couldn't fix. We just smiled and continued the tour. Incidentally, have you found the maker and model of the F connector that your un-named distributor will only sell to "professional" customers? It was in your office the last time you offered to find it. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/25/2014 6:18 AM, Jeff wrote:
Whilst I agree with your first point, Smiths Charts do not "explain what is happening inside of a piece of coax X inches long". They are an easy way to plot impedances, and show what happens if you *change* the length of coax, but more importantly they give you an easy way of working out how to match impedances (with or without any length of coax involved). They can also display other valuable quantities such as Q. jeff They do if you know how to use them properly. For instance, they will tell you when the reactive portion of the impedance is zero (neither capacitive nor inductive), which indicates resonance. They will also tell you the antenna's impedance at a specific frequency. Both can be used to indirectly determine antenna efficiency. Rubbish, they tell you nothing more than the impedance at the point that you wish to plot it. They tell you nothing about how well an antenna may, or may, not radiate. A 50 ohm resistor will be purely resistive (parasitic elements neglected) but won't radiate well. Also an antenna does not have to resonant to radiate well or have high efficiency. Jeff Keep thinking that, Jeff, while those who know how to use Smith Charts continue to design antennas. Your ignorance is underwhelming. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/25/2014 1:10 AM, Jeff Liebermann wrote:
On Fri, 24 Jan 2014 20:29:22 -0500, Jerry Stuckle wrote: Receiver sensitivity was 0.2 mv for 20db S+N/N ratio. I'll assume that you mean 0.2 microvolts, not millivolts. Also, nobody has uses 20dB S+N/N since about the 1960's except maybe the ARRL[1]. 12dB SINAD has been around since about the mid 1960's. http://en.wikipedia.org/wiki/SINAD I don't know how much better; the surplus signal generator I was using wasn't that accurate. At the time, I used a Gertsch FM-something. It's the box with only the left handle showing at the extreme right of the pictu http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html It wasn't every accurate, and not really intended to be used as a signal source. However, I had a precision step attenuator, and since the Gertsch factory was near my parents house, it wasn't too difficult to get it calibrated in trade for some grunt work. Yea, right. And your "homemade attenuator" was accurate to several microvolts. Tell us another one, Jeff! LMAO! And BTW - 'm' can also mean micro, especially when you don't have a Greek alphabet available. 'u' is not the same as the Greek 'mu' and can be confusing. Of course, using 'm' for both milli and micro can be confusing, unless you know the context. If you follow SI standards, the "m" means milli. http://physics.nist.gov/cuu/Units/prefixes.html I didn't say anything about SI standards. I was speaking of common usage. If you have a PC keyboard, try using the key combination: alt0181 on the number pad which produces a µ symbol. http://symbolcodes.tlt.psu.edu/accents/codealt.html Which doesn't work on all computers, all OS's, nor all charsets. [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. I suppose there might be some dinosaurs roaming the earth still talking about "20 dB quieting". Gee, most people learn to use pf right away - I know I did. And yes, 20 db quieting is still a standard used in FM. But you just continue to show your ignorance. You're only making a fool of yourself. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/25/2014 2:02 AM, Jeff Liebermann wrote:
On Fri, 24 Jan 2014 20:25:42 -0500, Jerry Stuckle wrote: On 1/24/2014 7:14 PM, Jeff Liebermann wrote: On Fri, 24 Jan 2014 13:04:48 -0500, Jerry Stuckle wrote: The easiest way of seeing it is looking at the output of both tube and transistorized transmitters on a spectrum analyzer. You will see much more hash on the transistorized transmitter. Amazing. You might see more hash with a synthesized transistor xmitter, but for crystal controlled, they noise is quite a bit less with transistors. You obviously don't use a decent spectrum analyzer. I've never seen or used an indecent spectrum analyzer. These are admittedly antiques, but do a tolerable job for most things I need: http://802.11junk.com/jeffl/pics/home/slides/test-equip-mess.html I wouldn't mind owning a much better spectrum analyzer, but I can't justify the expense. If I need one, I can usually borrow, or if really desperate, rent. But you know better than those who have used them regularly. You only continue to show your ignorance. Sure - WITH DUPLEXERS. I did it WITHOUT DUPLEXERS. A HUGE difference. But obviously one YOU DON'T UNDERSTAND. Do you even know what a duplexer is? (I really doubt it). I've been fairly polite up until now. I've tried to correct your mistakes, but have never stooped to personal insults and accusations. You don't seem to know how to engage in a technical discussion without being insulting. No more nice guy. You only continue to show your ignorance. And the fact you can't read. I've designed two 900 MHz commercial duplexers used in wireless SCADA systems. I've tuned probably around 50 assorted duplexers for a mixture of ham and commercial users. My only failure was when a local ham machined a rather nice looking duplexer out of 6" stove pipe, and then wondered why it didn't work as well as the silver plated variety. In my spare time, I'm trying to improve on the bad joke of a duplexer found in the Motorola MSF5000 UHF repeater. http://802.11junk.com/jeffl/K6BJ-MSF5000/ Yes, I think I know what a duplexer is. Who gives a damn about you and your duplexers you've supposedly designed? The fact here is, you can't read. And you only continue to show your ignorance. But I am curious - who designed and built your duplexers for you? Yes, nowadays, there are transistors with lower noise figures. But they are relatively expensive, and you won't find them in the less expensive receivers. Rubbish. pHEMT devices are available with 0.75dB NF at 1GHz for under $3/ea. For example: http://www.minicircuits.com/pdfs/PSA4-5043+.pdf Note that this isn't just a single device but a MMIC amplifier capable of belching 100 mw (+20dBm) with 1dB gain compression. Which you don't use in the front end of a receiver. But I see you don't understand anything that's been said in this thread, so no surprise there. Actually, you do, but I picked an example that could be used in a transmit chain, which I believe was the topic of discussion. ROFLMAO! I have yet to see a 100mw amplifier in the front end of a receiver. Probably because I don't know of any receivers which take 1mw input. Yet you claim you use them in the front end of a receiver. Your ignorance is astounding. No, AGC will not "try to keep the S/N ratio constant". It tries to keep the output of the IF constant. As the signal increases, the noise will decrease, improving the S/N ratio. But you also don't seem to understand how AGC works. I stand corrected. The rest of what I said about AGC is correct. You don't understand AGC, either. You probably don't even understand FM receivers don't have an AGC circuit. Even back in the early 70's, commercial tube VHF radios could easily get .15mv for 20db S+N/N ratio. Not much different than the transistorized versions today. I think you might mean 0.15 uv/12dB SINAD. A 0.15mv receiver would be considere comatose. No, I mean 20db S+N/N ratio. The equivalent SINAD would be somewhere around .12mv (or a bit less). Not at all "comatose". Please fix your abrevs. http://physics.nist.gov/cuu/Units/prefixes.html Please learn how to read. I never saw any tube receivers with 0.12µV/12dB SINAD sensitivity. However, that was at UHF. I don't recall the numbers I was getting for VHF and low band tube receivers. I could probably excavate some old Motorola Research line manuals and see what Motorola specifies in the manual. You're the only one who brought up UHF. But now you have to backpeddle again because your ignorance is so astounding. That must be because you were working on GE Pre-Prog. I worked with both Motorola and RCA sets (plus a few others which weren't quite as good). We were able to get them to .15mv. on VHF. The radios in the repeater rack are all Progress Line, not Pre-Prog. No experience with RCA, but the Motorola 5V, 40V, 80D and 140D were much the same as the Progress line radios. The UHF (T44) versions started out at about 0.5µV/12dB SINAD and slowly deteriorated to about 1µV. VHF receivers were somewhat better than that, but I don't recall the numbers. Then why did you say Pre-Prog? Backpeddling again? Or just showing your ignorance again. But then according to you, such a radio would be "comatose". I wonder just how bad your GE's were? The comatose was in reference to your abuse of the SI prefixes. Learn how to understand conversational writing. But then people interested in technical conversations discuss technical items. Trolls pick nits. It seems you are the latter. 1mv/12DB SINAD is terrible. Such a receiver would never have left our shop. Please fix your abrevs. http://physics.nist.gov/cuu/Units/prefixes.html Please stop trolling. 0.5mv wouldn't leave our shop, either. Please fix your abrevs. http://physics.nist.gov/cuu/Units/prefixes.html Please stop trolling. And both Motorola and RCA rigs would hold their sensitivity for much longer than that, even in a mobile installment. It was worse in repeater service, where we had to cram 3 repeaters in a rack because of limited floor space. Note the big squirrel cage blowers on the bottom of the rack. http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/Santiago-01.html Mobiles had to be retuned about once a year to maintain optimum performance. TX output tubes would last about 3 years. (6907 for GE and 2C39 for Motorola). We had multiple repeaters in a rack, also. But our Motorola and RCA rigs would last much longer than that without retuning. Of course, this was from the midwest, where the temperature only ran -20 to +110 F (that's Fahrenheit for the trolls), and the building was semi-unheated (actually it didn't need much heat due to all the transmitters. Cooling was another problem). Somewhat later, in the 1970's, I found myself designing marine radios. Typical VHF sensitivity was about 0.25uv/12dB SINAD using a dual gate MOSFET front end such as a 40673 or 3N212. We ocassionally used JFET's such as a U310 but the sensitivity was about the same. Yea, one of the shops I worked at sold similar quality rigs, mainly for those who wouldn't pay for a good RCA. The Motorola shop didn't sell anything else, of course. Interesting. I mention the front end devices and you immediately deduce everything about the product, the quality, and maybe even are able to guess the manufacturer? Wanna take a guess? You can even Google for the right answer without much difficulty. We were making marine radios in the USA for about 15 years. It wasn't the lack of quality that eventually killed the company. It was competition initially from Japan and later from China. Of course, you must prefer the current level of quality from China. Many years of training and experience and I know what's good in front ends and what isn't. And if your radios were any good, Chinese and Japanese companies wouldn't have killed your radios. There are many American companies who compete quite successfully with overseas companies based on higher quality - even though the price is higher. But then people don't want to look at the REAL reason their company failed. And although in my current business I can find many Chinese manufacturers, none of them have the quality my customers demand. Maybe in your designs, but not in the ones most of our clients demanded and paid for. You designed radios? Good to know. Our radios were used by the USCG, tug boats, inland waterways barges, bridges, and cruise ships. Those types of customers don't tolerate failures very gracefully. We also offered a lifetime warranty to underscore the point. Resurrecting 10 year old radios was not fun, but that's what it took to stay in business. Well, let's see. USCG typically purchased based on lowest bid (although like much of the government, they've learned and lowest bid is no longer the only factor). And as for the others - many of them also purchase based on lowest price. And just because maybe one or two cruise ships might have had your radios really doesn't mean anything. The fact you had to provide a lifetime warranty to sell them is quite telling, however. Incidentally, my best day was when I visited the USCG repair depot on Yerba Buena Island, and saw a rather large pile of Motorola Modar radios. When I asked, I was told those were the one's they couldn't fix. We just smiled and continued the tour. Which means what - the technicians weren't very competent? When I worked for a Motorola shop, there was NEVER a radio we couldn't fix. Incidentally, have you found the maker and model of the F connector that your un-named distributor will only sell to "professional" customers? It was in your office the last time you offered to find it. Sure, but I really don't give a damn about what trolls want. So I'm not going to bother to dig it out. But as I said - I can't post a picture here, and you can't access the distributor's site without an account. So it really doesn't matter, anyway. And I know it really torques you to know there's something others can get but you can't. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
In message , Jeff Liebermann
writes [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. But have you started referring to them as "puffs"? This is the normal UK colloquialism for picofarads, but I believe it raises the American eyebrow! -- Ian |
Relationship Between Antenna Efficiency and Received Signal Strength
"Ian Jackson" [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. But have you started referring to them as "puffs"? This is the normal UK colloquialism for picofarads, but I believe it raises the American eyebrow! I too was using the uuf and uf. Then it took me a while to get used to the pf. I still can not relate to the nanofarad. Every time I see that nanofarad I have to put the numbers on a piece of paper and convert it to uu or u. I have often heard the uuf referred to as puffs. After the first couple of times I never gave it a second thought when someone says puffs. I am in the US. I still use Hz and cycles without giving it a thought as to which one I am saying. Just can not get it my head not to say cycles when I should be saying Hz. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
Relationship Between Antenna Efficiency and Received Signal Strength
"Jeff Liebermann" wrote in message ... At the time, I used a Gertsch FM-something. It's the box with only the left handle showing at the extreme right of the pictu http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html I can not tell what the Gertsch is from the pix. I have a Singer/Gertsch FM-10C, but it looks to be older than that. Do see the old generator next to the scope. I have one like that and play with it from time to time. Checked the output amplitude of it with my hp 8924c and it seems to be very close allowing for the fact it is an analog dial and you have to set it to the mark on the meter. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/26/2014 9:12 AM, Ian Jackson wrote:
In message , Jeff Liebermann writes [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. But have you started referring to them as "puffs"? This is the normal UK colloquialism for picofarads, but I believe it raises the American eyebrow! Yep, I first heard the term "puffs" here in the U.S. back in the 60's. Still used a lot by techs and engineers in the field. I haven't heard micro-micro farads in decades. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/26/2014 5:09 AM, Jeff wrote:
Rubbish, they tell you nothing more than the impedance at the point that you wish to plot it. They tell you nothing about how well an antenna may, or may, not radiate. A 50 ohm resistor will be purely resistive (parasitic elements neglected) but won't radiate well. Also an antenna does not have to resonant to radiate well or have high efficiency. Jeff Keep thinking that, Jeff, while those who know how to use Smith Charts continue to design antennas. Your ignorance is underwhelming. Well Jerry, please help me increase my knowledge. Please tell me now to show what "goes on *inside* a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart. Jeff I'll tell you what, troll. You go to college. Get a EE degree. Learn the math and the theory. Them maybe you can understand basics and we can discuss the subject intelligently (although I doubt it). Usenet is not the place to try to teach you four years of math, physics and electronics. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/26/2014 11:12 AM, Jeff wrote:
On 26/01/2014 15:50, Jerry Stuckle wrote: On 1/26/2014 5:09 AM, Jeff wrote: Rubbish, they tell you nothing more than the impedance at the point that you wish to plot it. They tell you nothing about how well an antenna may, or may, not radiate. A 50 ohm resistor will be purely resistive (parasitic elements neglected) but won't radiate well. Also an antenna does not have to resonant to radiate well or have high efficiency. Jeff Keep thinking that, Jeff, while those who know how to use Smith Charts continue to design antennas. Your ignorance is underwhelming. Well Jerry, please help me increase my knowledge. Please tell me now to show what "goes on *inside* a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart. Jeff I'll tell you what, troll. You go to college. Get a EE degree. Learn the math and the theory. Them maybe you can understand basics and we can discuss the subject intelligently (although I doubt it). Been there done that, and spend 30+ designing and specifying radio equipment, and using Smith charts. Yea, right. I'll take it as a "no I can't" then. Which of course is true you can't how what "goes on *inside* a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart. Nope, I'm not even going to try to teach the pig to sing, especially in a newsgroup. But trolls don't understand that. Try reading Mr Smith's excellent book on his Smith Chart and you might find out what it can and can't do!!! Jeff Try getting your EE degree along with the math, physics and electrical theory. Then maybe we can discuss this intelligently. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On Sun, 26 Jan 2014 14:12:30 +0000, Ian Jackson
wrote: In message , Jeff Liebermann writes [1] It took me about 10 years to stop using micro-microfarads and switch to picofarads. But have you started referring to them as "puffs"? This is the normal UK colloquialism for picofarads, but I believe it raises the American eyebrow! I use it and it's quite common among my older friends and accomplices. I don't know about the younger ones. It's not something that gets my attention as I use both terms interchangeably. That might be due to my working for a company full of British engineers (Granger Assoc). At one point, I accidentally developed a British accent and increase my talking speed by about 25%. Fortunately, I lost both as I moved on to other things. However, I vaguely recall that I used "puffs" before I started working there. However, in another life, I found myself giving presentations to other engineers, some of which were from foreign countries. To avoid confusion, I made it a point of avoiding slang terminology and only using standard prefixes. It's been mostly like that ever since. At a previous employer, there was also a move to butcher the uH into an "ugh". Thankfully, that went nowhere although I have heard it used a few times over the years. Currently, I'm also having problems using Becquerels and still prefer to use the older "clicks per minute" or curies. (One Bq is one disintegration per second). There are other old/new terms used in radiation, which seem to cause more confusion than enlightenment. It will probably take a generation to sort things out. I can really create confusion when I do calculations in mixed metric and US units of measure. It doesn't bother me much as I have some of the conversions memorized, but it certainly drives everyone else nuts. To maintain sanity, I use metric for engineering, and US at the supermarket. I refuse to use Imperial for anything other than inflating my gasoline mileage figures. I sometimes fool myself when I do mixed units of measure calcs, and forget to qualify the "ton" as a "metric ton". Specialists in any industry tend to develop their own language and slang terminology. I suspect that few people outside the computer biz know that a "blog" is really a "web log". Do you still call a telephone a "blower" (even though it's really a naval term)? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
On Sun, 26 Jan 2014 10:03:55 -0500, "Ralph Mowery"
wrote: I too was using the uuf and uf. Then it took me a while to get used to the pf. I still can not relate to the nanofarad. Every time I see that nanofarad I have to put the numbers on a piece of paper and convert it to uu or u. Thanks for reminding me. I have exactly the same problem. Old habits die hard. I don't think I've ever used nanofarads in any design. Some of the software I use offers an option to disable the use of nanofarads. However, as new versions arrive, I'm seeing that less and less. I still use Hz and cycles without giving it a thought as to which one I am saying. Just can not get it my head not to say cycles when I should be saying Hz. That one was easy for me. Cycles per second is just too many syllables to easily roll off the tongue. I usually favor the shortest and most abbreviated term. When the Hz arrived, I embraced it gladly and immediately abandoned CPS. Where we came from: http://www.hemyockcastle.co.uk/measure.htm With that history of units of measure, I would hate to guess where we're going. I did invent a unit of measure which seems to have stuck for a time at a former college. During college, I built a device to quantify female desirability. It was an IR detector that basically measured the mount of exposed skin. I needed a unit of measure for female desirability which became the milli-Helen. Since Helen of Troy launched 1000 ships, 1 milli-Helen would launch 1 ship. The negative was also true as negative 1 milli-Helen would sink 1 ship. Unfortunately, it somewhat backfired and failed to provide me with any additional dates and lady friends. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
On Sun, 26 Jan 2014 10:25:16 -0500, "Ralph Mowery"
wrote: "Jeff Liebermann" wrote in message .. . At the time, I used a Gertsch FM-something. It's the box with only the left handle showing at the extreme right of the pictu http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html I can not tell what the Gertsch is from the pix. I have a Singer/Gertsch FM-10C, but it looks to be older than that. I tried to find a better photo of the generator, but couldn't. It's a Gertsch FM-7 and DM-3 modulation meter combination, which is partly shown in the photo. I think it looked something like this: http://www.ebay.com/itm/141159577401 The Measurements (later Boonton) Model 80 was my "calibrated" signal source. I let it drift onto frequency using the FM-7, and used it to measure sensitivity. If left on continuously, it was stable enough for the old 50 KHz wide band radios. Do see the old generator next to the scope. I have one like that and play with it from time to time. http://www.ko4bb.com/Manuals/09)_Misc_Test_Equipment/Boonton/Boonton_Model_80_Manual.pdf I still have some acorn tubes for it buried somewhere. Checked the output amplitude of it with my hp 8924c and it seems to be very close allowing for the fact it is an analog dial and you have to set it to the mark on the meter. I had ours calibrated along with the FM-7. In order to operate in the UHF commercial band (about 463 MHz), we had to use the 3rd harmonic through a multiplier. It also lacked FM modulation which I added with a varactor (varicap) diode. The techs said it was quite accurate and fairly stable in the UHF region. I also had another RF source consisting of the exciter chain from an old radio. Not the best, but since it was crystal controlled, it was at least stable. For the late 1960's and early 1970's, it wasn't a bad arrangement. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
"Jeff Liebermann" wrote in message ... On Sun, 26 Jan 2014 10:25:16 -0500, "Ralph Mowery" wrote: "Jeff Liebermann" wrote in message . .. At the time, I used a Gertsch FM-something. It's the box with only the left handle showing at the extreme right of the pictu http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html I can not tell what the Gertsch is from the pix. I have a Singer/Gertsch FM-10C, but it looks to be older than that. I tried to find a better photo of the generator, but couldn't. It's a Gertsch FM-7 and DM-3 modulation meter combination, which is partly shown in the photo. I think it looked something like this: http://www.ebay.com/itm/141159577401 The Measurements (later Boonton) Model 80 was my "calibrated" signal source. I let it drift onto frequency using the FM-7, and used it to measure sensitivity. If left on continuously, it was stable enough for the old 50 KHz wide band radios. Do see the old generator next to the scope. I have one like that and play with it from time to time. http://www.ko4bb.com/Manuals/09)_Misc_Test_Equipment/Boonton/Boonton_Model_80_Manual.pdf I still have some acorn tubes for it buried somewhere. The Boonton you have is the AM modle. The one I have is the FM modle and the number is T1035B. From the pix you had it, at first glance it looked like a differant modle as part of it was hidden. Mine works through the 450 mhz reagon. It does have a scale for something between 800 to 900 mhz that is not calibrated. Also there is another oscillator that is not calibrated, but adjustiable that covers some low frequencies of between maybe 3 to 30 mhz. I think that is the one or maybe a later transistorised version that is shown in some of the old GE Mastr ll books. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
Relationship Between Antenna Efficiency and Received Signal Strength
In message , Jeff Liebermann
writes When the Hz arrived, I embraced it gladly and immediately abandoned CPS. I didn't like hertzes when they we foisted upon us - and I still don't (although I won't go as far as to rebel against them). In a spoken sentence, they always seem to introduce a bit of a hiccup, whereas "cycles" seems to roll more easily off the tongue (even if those using it really mean cycles per second). -- Ian |
Relationship Between Antenna Efficiency and Received Signal Strength
On Sun, 26 Jan 2014 19:23:04 +0000, Ian Jackson
wrote: In message , Jeff Liebermann writes When the Hz arrived, I embraced it gladly and immediately abandoned CPS. I didn't like hertzes when they we foisted upon us - and I still don't (although I won't go as far as to rebel against them). In a spoken sentence, they always seem to introduce a bit of a hiccup, whereas "cycles" seems to roll more easily off the tongue (even if those using it really mean cycles per second). That's because of the English accent. Try pronouncing it as "hurts". In New York, the pronunciation is something like "hoits". At Avis rent-a-car, Hertz is never mentioned. Drivel: Marketing people like to identify their products with names and letters that make the speaker smile when pronouncing it. The common "say cheese" in photography is an example. "Cycles" doesn't quite make one smile, but it's close. "Hertz" is produces almost a frown, which may explain why you're having difficulties with it. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
In message , Jeff Liebermann
writes On Sun, 26 Jan 2014 19:23:04 +0000, Ian Jackson wrote: In message , Jeff Liebermann writes When the Hz arrived, I embraced it gladly and immediately abandoned CPS. I didn't like hertzes when they we foisted upon us - and I still don't (although I won't go as far as to rebel against them). In a spoken sentence, they always seem to introduce a bit of a hiccup, whereas "cycles" seems to roll more easily off the tongue (even if those using it really mean cycles per second). That's because of the English accent. Try pronouncing it as "hurts". In New York, the pronunciation is something like "hoits". At Avis rent-a-car, Hertz is never mentioned. Drivel: Marketing people like to identify their products with names and letters that make the speaker smile when pronouncing it. The common "say cheese" in photography is an example. "Cycles" doesn't quite make one smile, but it's close. "Hertz" is produces almost a frown, which may explain why you're having difficulties with it. Hertz certainly hurts a bit when you say it - especially if you pronounce it correctly, as 'hairts' (almost a grimace). 'Hertz' requires more breath than 'cycles', so prior to saying it, you often pause for a momentary intake of air. Also, the units 'Hz', 'kHz' and 'MHz' don't lend themselves to pronunciation, whereas 'cycles', 'kay-sees' and 'megs' do. Just to get back on topic, since we started using Hz, I'm sure antennas have become less efficient and signal strengths lower - and it's certain that QRM is now much worse. -- Ian |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/27/2014 2:40 AM, Jeff wrote:
Jeff Try getting your EE degree along with the math, physics and electrical theory. Then maybe we can discuss this intelligently. I am offering to discuss this intelligently by asking you to explain and enlighten me as to how a Smith chart shows what "goes on inside a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart, but you are the one coming back with (incorrect) personal insults!! Jeff When you get the sufficient background in electronics, math and physics, we can discuss this intelligently. Until then, it's like teaching a pig to sing. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On Mon, 27 Jan 2014 08:44:27 +0000, Ian Jackson
wrote: Hertz certainly hurts a bit when you say it - especially if you pronounce it correctly, as 'hairts' (almost a grimace). Yep. The German pronunciation. For visitors to the USA: http://www.youtube.com/watch?v=BdkaD99XJ5I 'Hertz' requires more breath than 'cycles', so prior to saying it, you often pause for a momentary intake of air. Well, let's see if that's true. I just tried it on myself and did not exactly get the desired effect. For volume, I just hung a piece of paper in front of my mouth and looked for deflection. The trick is to say the various words at a constant volume or the results are worthless. I used a vu meter display on my smartphone to insure that I was talking at the same level. From the paper deflection, I would estimate that I move more air saying cycles because of the two syllables. However, the peak exhaust volume seems to be higher when saying "Hertz". I then did the same test with a microphone and audio spectrum analyzer program (Spectrum Lab 2.79). It showed somewhat different results. Both words showed a fair number of frequency component peaks of roughly the same amplitude. However, the word "cycles" had more almost identical peaks thus indicating that it required more energy to produce. At this point, I'm not sure if I should believe my paper test, or the spectrum analyzer results. Also, the units 'Hz', 'kHz' and 'MHz' don't lend themselves to pronunciation, whereas 'cycles', 'kay-sees' and 'megs' do. Good point. Abbrevs are important. That might explain the tendency for hams to prefer using wavelengths (i.e. 80 meters) rather than the more accurate and specific equivalent frequencies. I use the various frequency terms far more often in writing than in speech, where such abbreviations are of lesser importance. I don't have much of problem with the various SI units prefixes to Hertz, but I certainly have problems with acronymic contractions such as CPS (cycles per second) which has more than once been confused with the local Child Protective Services. I think it best to use Hertz, which does not have this problem. Just to get back on topic, since we started using Hz, I'm sure antennas have become less efficient and signal strengths lower - and it's certain that QRM is now much worse. The problem is much worse than that. When I first started in ham radio, I had a full head of hair, a steady hand, a reasonable bank balance, and a positive attitude. After being involved in ham radio for many years, the hair is falling out, the hand is shaky, the bank balance depleted, and the attitude quite cynical. Obviously, exposure to ham radio and its associated RF fields has caused this unnatural deterioration. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship:: Now Hertz
"Jeff Liebermann" wrote in message ... On Mon, 27 Jan 2014 08:44:27 +0000, Ian Jackson wrote: 'Hertz' requires more breath than 'cycles', so prior to saying it, you often pause for a momentary intake of air. Well, let's see if that's true. I just tried it on myself and did not exactly get the desired effect. For volume, I just hung a piece of paper in front of my mouth and looked for deflection. The trick is to say the various words at a constant volume or the results are worthless. I used a vu meter display on my smartphone to insure that I was talking at the same level. From the paper deflection, I would estimate that I move more air saying cycles because of the two For a true test stick your finger in a light socket and see if you say Hertz or cycles. You may even say ouch or a few other choice words. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/27/2014 12:31 PM, Jeff wrote:
On 27/01/2014 13:37, Jerry Stuckle wrote: On 1/27/2014 2:40 AM, Jeff wrote: Jeff Try getting your EE degree along with the math, physics and electrical theory. Then maybe we can discuss this intelligently. I am offering to discuss this intelligently by asking you to explain and enlighten me as to how a Smith chart shows what "goes on inside a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart, but you are the one coming back with (incorrect) personal insults!! Jeff When you get the sufficient background in electronics, math and physics, we can discuss this intelligently. Until then, it's like teaching a pig to sing. You really are a very rude person. Jeff Oh, because I won't give you a the equivalent of a four-year degree for free on usenet? You really are a troll. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On Sun, 26 Jan 2014 13:20:29 -0500, "Ralph Mowery"
wrote: The Boonton you have is the AM modle. Yep. AM only. Someone modified it to look like the Motorola T1034 or T1035. I found some info and schematics on that series of generators: http://www.repeater-builder.com/motorola/test-equipment/moto-test-equip-index.html Search for the T-1034 section. We had three of the Measurements Model 80 generators. One for the service van, one for the shop, and one for spare parts. The one I have is the FM modle and the number is T1035B. From the pix you had it, at first glance it looked like a differant modle as part of it was hidden. Sorry. I'll see if I can find a better photo of the shop. Mine works through the 450 mhz reagon. It does have a scale for something between 800 to 900 mhz that is not calibrated. Also there is another oscillator that is not calibrated, but adjustiable that covers some low frequencies of between maybe 3 to 30 mhz. I hadn't seen any that did that. All the Measurements generators that we had were AM only. I think that is the one or maybe a later transistorised version that is shown in some of the old GE Mastr ll books. I'll look in my pile of MSTR II manuals tonite. Drivel: I just found a box of Motorola Buyers Guides from the 1970's in the office. Office closet archaeology is so much fun. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 2:38 AM, Jeff wrote:
When you get the sufficient background in electronics, math and physics, we can discuss this intelligently. Until then, it's like teaching a pig to sing. You really are a very rude person. Jeff Oh, because I won't give you a the equivalent of a four-year degree for free on usenet? You really are a troll. No, because when challenged to prove the assertions that you made you evade answering by using rude personal remarks. Jeff Yes, because I'm not going to give you the equivalent of a four-year degree for free on usenet. You get sufficient background to discuss this intelligently and we can continue, troll. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 11:26 AM, Jeff wrote:
No, because when challenged to prove the assertions that you made you evade answering by using rude personal remarks. Jeff Yes, because I'm not going to give you the equivalent of a four-year degree for free on usenet. You get sufficient background to discuss this intelligently and we can continue, troll. No need for a degree course just simple explanations from you as to how a Smith Chart can show the efficiency of an antenna, and how one can show what goes on *inside* a piece of coax, which is what you maintained. Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 2:25 PM, Jeff wrote:
Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. And just like a troll, you don't respond to my comments. They were REAL responses - but ones you can't answer. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
Jerry Stuckle wrote:
On 1/28/2014 2:25 PM, Jeff wrote: Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. Not quite; a Smith chart is a nomgraph of complex impedance usually noralized to one. The data could come from "mathematical forumulae" but usually comes from measured data in which case the "mathematical forumulae" amounts to normalizing the impedance to one. From a Smith chart, one can obtain impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. -- Jim Pennino |
Relationship Between Antenna Efficiency and Received Signal Strength
|
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 7:40 PM, wrote:
Jerry Stuckle wrote: On 1/28/2014 5:10 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 2:25 PM, Jeff wrote: Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. Not quite; a Smith chart is a nomgraph of complex impedance usually noralized to one. The data could come from "mathematical forumulae" but usually comes from measured data in which case the "mathematical forumulae" amounts to normalizing the impedance to one. From a Smith chart, one can obtain impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
Jerry Stuckle wrote:
On 1/28/2014 7:40 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 5:10 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 2:25 PM, Jeff wrote: Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. Not quite; a Smith chart is a nomgraph of complex impedance usually noralized to one. The data could come from "mathematical forumulae" but usually comes from measured data in which case the "mathematical forumulae" amounts to normalizing the impedance to one. From a Smith chart, one can obtain impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. -- Jim Pennino |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 9:09 PM, wrote:
Jerry Stuckle wrote: On 1/28/2014 7:40 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 5:10 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 2:25 PM, Jeff wrote: Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. Not quite; a Smith chart is a nomgraph of complex impedance usually noralized to one. The data could come from "mathematical forumulae" but usually comes from measured data in which case the "mathematical forumulae" amounts to normalizing the impedance to one. From a Smith chart, one can obtain impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. A huge difference - which you obviously don't understand, either. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
Jerry Stuckle wrote:
On 1/28/2014 9:09 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 7:40 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 5:10 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 2:25 PM, Jeff wrote: Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. Not quite; a Smith chart is a nomgraph of complex impedance usually noralized to one. The data could come from "mathematical forumulae" but usually comes from measured data in which case the "mathematical forumulae" amounts to normalizing the impedance to one. From a Smith chart, one can obtain impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. Given care in gathering the data and plotting it, a Smith chart gives answers more than accurate enough for almost all practical applicatons. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. One does NOT need to understand the underlying math to use a Smith chart nor any math to get relevant answers from it. That was the whole point of using a Smith chart. A huge difference - which you obviously don't understand, either. You sound like someone who's total exposure to Smith charts is a web page overview. -- Jim Pennino |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 9:53 PM, wrote:
Jerry Stuckle wrote: On 1/28/2014 9:09 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 7:40 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 5:10 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 2:25 PM, Jeff wrote: Bur of course you won't/can't so I will expect more rude comments from you. Jeff When you get the necessary background to understand how it works, then we can discuss it intelligently. But you even think a smith chart can't be used for antennas. So much for your knowledge. And also please point out exactly where I said a smith chart could be used to show the efficiency of an antenna, or what goes on inside a piece of coax. But you can't - trolls are good at twisting words and coming up with unsubstantiated claims. AS I expected more rude personal comments and no real response. It would appear that anyone who disagrees with you is a troll. I think that you have show yourself for what you are in this and other threads, and are incapable of rational discussion. It is you who are the troll. I have nothing more to say as you do not wish to justify your arguments. Jeff If you understood ANYTHING about Smith Charts, you would understand they are the graphical representation of the results of mathematical forumulae. And you obviously don't have the background to understand the math, so any intelligent discussion is not possible. Not quite; a Smith chart is a nomgraph of complex impedance usually noralized to one. The data could come from "mathematical forumulae" but usually comes from measured data in which case the "mathematical forumulae" amounts to normalizing the impedance to one. From a Smith chart, one can obtain impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability. I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. Given care in gathering the data and plotting it, a Smith chart gives answers more than accurate enough for almost all practical applicatons. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. One does NOT need to understand the underlying math to use a Smith chart nor any math to get relevant answers from it. That was the whole point of using a Smith chart. A huge difference - which you obviously don't understand, either. You sound like someone who's total exposure to Smith charts is a web page overview. You have no idea how a Smith Chart works, that plain. And you don't understand it. You don't need to know how a radio works to use it. But you do have to understand it to design or fix it. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
Jerry Stuckle wrote:
On 1/28/2014 9:53 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 9:09 PM, wrote: Jerry Stuckle wrote: snip I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. Given care in gathering the data and plotting it, a Smith chart gives answers more than accurate enough for almost all practical applicatons. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. One does NOT need to understand the underlying math to use a Smith chart nor any math to get relevant answers from it. That was the whole point of using a Smith chart. A huge difference - which you obviously don't understand, either. You sound like someone who's total exposure to Smith charts is a web page overview. You have no idea how a Smith Chart works, that plain. And you don't understand it. It seems I understand it far better than you do, but then I actually have used them as opposed to having just read a web page overview. You don't need to know how a radio works to use it. But you do have to understand it to design or fix it. Finally you understand; you don't need to know the math to use and get answers from a Smith chart but you do need to know the math to design a Smith chart. That was the whole point of a Smith chart; to remove the tedious math. -- Jim Pennino |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/28/2014 11:23 PM, wrote:
Jerry Stuckle wrote: On 1/28/2014 9:53 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 9:09 PM, wrote: Jerry Stuckle wrote: snip I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. Given care in gathering the data and plotting it, a Smith chart gives answers more than accurate enough for almost all practical applicatons. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. One does NOT need to understand the underlying math to use a Smith chart nor any math to get relevant answers from it. That was the whole point of using a Smith chart. A huge difference - which you obviously don't understand, either. You sound like someone who's total exposure to Smith charts is a web page overview. You have no idea how a Smith Chart works, that plain. And you don't understand it. It seems I understand it far better than you do, but then I actually have used them as opposed to having just read a web page overview. You don't need to know how a radio works to use it. But you do have to understand it to design or fix it. Finally you understand; you don't need to know the math to use and get answers from a Smith chart but you do need to know the math to design a Smith chart. That was the whole point of a Smith chart; to remove the tedious math. The whole design of the Smith chart was to give an approximation of what occurs. But you wouldn't know that from the web pages you read. And I never said you had to know the math to USE the Smith Chart. I said you had to know the math to UNDERSTAND the Smith Chart. But you can't even understand that difference. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
Jerry Stuckle wrote:
On 1/28/2014 11:23 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 9:53 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 9:09 PM, wrote: Jerry Stuckle wrote: snip I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. Given care in gathering the data and plotting it, a Smith chart gives answers more than accurate enough for almost all practical applicatons. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. One does NOT need to understand the underlying math to use a Smith chart nor any math to get relevant answers from it. That was the whole point of using a Smith chart. A huge difference - which you obviously don't understand, either. You sound like someone who's total exposure to Smith charts is a web page overview. You have no idea how a Smith Chart works, that plain. And you don't understand it. It seems I understand it far better than you do, but then I actually have used them as opposed to having just read a web page overview. You don't need to know how a radio works to use it. But you do have to understand it to design or fix it. Finally you understand; you don't need to know the math to use and get answers from a Smith chart but you do need to know the math to design a Smith chart. That was the whole point of a Smith chart; to remove the tedious math. The whole design of the Smith chart was to give an approximation of what occurs. But you wouldn't know that from the web pages you read. The whole point of the Smith chart was to provide a tool to solve practical problems in the real world. The problems solved by the Smith chart do not need 10 decimal places of accuracy and the accuracy of a Smith chart is on the same level as a slide rule, which was the standard instrument for solving problems at the time the Smith chart was invented. All your puffery about approximation is just nonsensee. And I never said you had to know the math to USE the Smith Chart. I said you had to know the math to UNDERSTAND the Smith Chart. But you can't even understand that difference. You only need to know the math to understand HOW the Smith chart works, but not to use a Smith chart and get real world answers to real world problems. -- Jim Pennino |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/29/2014 11:00 AM, wrote:
Jerry Stuckle wrote: On 1/28/2014 11:23 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 9:53 PM, wrote: Jerry Stuckle wrote: On 1/28/2014 9:09 PM, wrote: Jerry Stuckle wrote: snip I KNOW what a Smith Chart is. But unlike you, I UNDERSTAND the math behind it. It's all about the math. Actually a Smith chart is all about AVOIDING the math which was very difficult and time consuming to do in the pre-computer days. It's all based on the math. And if you understand the math, you can use a Smith Chart much more effectively. And it wasn't all THAT time consuming - we had to do it with a slipstick, paper and pencil. No PC's (or even calculators) in those days. It sure as hell WAS time consuming WITHOUT a Smith chart. And of course the Smith chart is BASED on math, though you didn't need to know the underlaying equations to use one. WITH a Smith chart there was little to no math required, that is the whole point of a Smith chart. No, a Smith Chart just gives an approximation for the forumlae involved. Given care in gathering the data and plotting it, a Smith chart gives answers more than accurate enough for almost all practical applicatons. You don't necessarily need the math to USE a Smith Chart. But you do to UNDERSTAND it. One does NOT need to understand the underlying math to use a Smith chart nor any math to get relevant answers from it. That was the whole point of using a Smith chart. A huge difference - which you obviously don't understand, either. You sound like someone who's total exposure to Smith charts is a web page overview. You have no idea how a Smith Chart works, that plain. And you don't understand it. It seems I understand it far better than you do, but then I actually have used them as opposed to having just read a web page overview. You don't need to know how a radio works to use it. But you do have to understand it to design or fix it. Finally you understand; you don't need to know the math to use and get answers from a Smith chart but you do need to know the math to design a Smith chart. That was the whole point of a Smith chart; to remove the tedious math. The whole design of the Smith chart was to give an approximation of what occurs. But you wouldn't know that from the web pages you read. The whole point of the Smith chart was to provide a tool to solve practical problems in the real world. The problems solved by the Smith chart do not need 10 decimal places of accuracy and the accuracy of a Smith chart is on the same level as a slide rule, which was the standard instrument for solving problems at the time the Smith chart was invented. No, a slipstick in the hands of someone proficient in its use is much more accurate than a Smith Chart. All your puffery about approximation is just nonsensee. You say that because you don't have the math to understand how a Smith Chart works. Since you don't understand, no one else can, either. ROFLMAO! And I never said you had to know the math to USE the Smith Chart. I said you had to know the math to UNDERSTAND the Smith Chart. But you can't even understand that difference. You only need to know the math to understand HOW the Smith chart works, but not to use a Smith chart and get real world answers to real world problems. I NEVER said you needed to know the math to USE a Smith Chart. I said you need the math to UNDERSTAND the Smith Chart. Which you obviously don't, or you wouldn't be making such comments. But then I expect nothing less from the troll. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
Relationship Between Antenna Efficiency and Received Signal Strength
Jerry Stuckle wrote:
On 1/29/2014 11:00 AM, wrote: Jerry Stuckle wrote: snip The whole design of the Smith chart was to give an approximation of what occurs. But you wouldn't know that from the web pages you read. The whole point of the Smith chart was to provide a tool to solve practical problems in the real world. The problems solved by the Smith chart do not need 10 decimal places of accuracy and the accuracy of a Smith chart is on the same level as a slide rule, which was the standard instrument for solving problems at the time the Smith chart was invented. No, a slipstick in the hands of someone proficient in its use is much more accurate than a Smith Chart. Utter nonsense; a decent sized Smith chart with a sharp pencil is every bit as accurate as a slide rule, and for the answers obtained, even more accurate as a Smith chart does NOT lose digits in intermediate calculations. All your puffery about approximation is just nonsensee. You say that because you don't have the math to understand how a Smith Chart works. I say that because I have actually used Smith charts to solve real world problems. FYI once the HP65 came out, I abandoned Smith charts, Nyquist plots, and a whole raft of other such aids for programs on the little tapes I wrote. Since you don't understand, no one else can, either. Just another babbling ad hominem from the guy who by declaration is never wrong about anything. ROFLMAO! And I never said you had to know the math to USE the Smith Chart. I said you had to know the math to UNDERSTAND the Smith Chart. But you can't even understand that difference. You only need to know the math to understand HOW the Smith chart works, but not to use a Smith chart and get real world answers to real world problems. I NEVER said you needed to know the math to USE a Smith Chart. I said you need the math to UNDERSTAND the Smith Chart. Which you obviously don't, or you wouldn't be making such comments. Nope, only if you mean understand how to design a Smith chart. You need no math to read SWR from a Smith chart or to know what SWR is. But then I expect nothing less from the troll. I expect nothing more but babbling, high horse nonsense from the self proclaimed master of everything. -- Jim Pennino |
Relationship Between Antenna Efficiency and Received Signal Strength
On 1/29/2014 11:41 AM, wrote:
Jerry Stuckle wrote: On 1/29/2014 11:00 AM, wrote: Jerry Stuckle wrote: snip The whole design of the Smith chart was to give an approximation of what occurs. But you wouldn't know that from the web pages you read. The whole point of the Smith chart was to provide a tool to solve practical problems in the real world. The problems solved by the Smith chart do not need 10 decimal places of accuracy and the accuracy of a Smith chart is on the same level as a slide rule, which was the standard instrument for solving problems at the time the Smith chart was invented. No, a slipstick in the hands of someone proficient in its use is much more accurate than a Smith Chart. Utter nonsense; a decent sized Smith chart with a sharp pencil is every bit as accurate as a slide rule, and for the answers obtained, even more accurate as a Smith chart does NOT lose digits in intermediate calculations. I see you never used a slipstick, either. It was a required course when I was in college - and we had to be QUITE accurate. All your puffery about approximation is just nonsensee. You say that because you don't have the math to understand how a Smith Chart works. I say that because I have actually used Smith charts to solve real world problems. You say that because you don't have the math to understand how a Smith Chart works. FYI once the HP65 came out, I abandoned Smith charts, Nyquist plots, and a whole raft of other such aids for programs on the little tapes I wrote. Wow. Gee, I'm impressed! ROFLMAO! Since you don't understand, no one else can, either. Just another babbling ad hominem from the guy who by declaration is never wrong about anything. Just an acute observation about what you say. ROFLMAO! And I never said you had to know the math to USE the Smith Chart. I said you had to know the math to UNDERSTAND the Smith Chart. But you can't even understand that difference. You only need to know the math to understand HOW the Smith chart works, but not to use a Smith chart and get real world answers to real world problems. I NEVER said you needed to know the math to USE a Smith Chart. I said you need the math to UNDERSTAND the Smith Chart. Which you obviously don't, or you wouldn't be making such comments. Nope, only if you mean understand how to design a Smith chart. No, I mean to UNDERSTAND the Smith Chart. Anyone can be an appliance operator. You need no math to read SWR from a Smith chart or to know what SWR is. I never said you couldn't USE it. But you obviously don't UNDERSTAND it. But then I expect nothing less from the troll. I expect nothing more but babbling, high horse nonsense from the self proclaimed master of everything. No, not master of anything. But I know a lot more than trolls like you do. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
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