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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Recommendation for electronics forums?
David Nebenzahl wrote:
I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. Now, if the answer turns out to be "What, are you nuts? There ain't no such thing!", then I guess I can live with that ... Give this one a try... Everything there from dummies to experts. http://www.electro-tech-online.com/ -- David dgminala at mediacombb dot net |
#2
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Recommendation for electronics forums?
I'm looking for an online electronics forum (web-based) where I can post
some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. Now, if the answer turns out to be "What, are you nuts? There ain't no such thing!", then I guess I can live with that ... -- The phrase "jump the shark" itself jumped the shark about a decade ago. - Usenet |
#3
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Recommendation for electronics forums?
In article ,
David Nebenzahl wrote: The subject of my current research is the ins and outs of op amps. A little pun, there? |
#4
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Recommendation for electronics forums?
On Sat, 19 Mar 2011 17:39:54 -0800, David Nebenzahl
wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. Now, if the answer turns out to be "What, are you nuts? There ain't no such thing!", then I guess I can live with that ... One would be the combined forum for Nuts & Volts magazine and Servo magazine at http://forums.servomagazine.com. Then there are the forums run by Circuit Cellar at http://bbs.circuitcellar.com. Also Elektor over at http://www.elektor.com/ -- Rich Webb Norfolk, VA |
#5
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Recommendation for electronics forums?
Smitty Two wrote: In article , David Nebenzahl wrote: The subject of my current research is the ins and outs of op amps. A little pun, there? A bit bipolar, if you ask me... -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#6
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Recommendation for electronics forums?
David Nebenzahl wrote:
I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Not quite a web forum, but more personal. Geoff. -- Geoffrey S. Mendelson N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. |
#7
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. ** That is in the same class as needing a pint of milk and so buying a cow. ..... Phil |
#8
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Recommendation for electronics forums?
David Nebenzahl wrote:
I agree, not a very good piece of advice. It's the difference between learning to ride a bicycle by going to a riding club versus sitting on stools and moving your feet. (first told to me in the 1960's to describe programing classes that had no access to a computer). Sorry, but IMHO the level of expertise and education you will get on a web forum is pretty low. Why not get your education from people who actually use the things and follow an almost 100 year tradition of educating newcomers? In my experience the engineers who did it "for a job" were boring and uninventive, the passionate ones were hams. The amount of effort is nothing like it used to be, you can earn a ham license in a weekend. You just need to answer 75% of 50 multiple choice questions corrent about basic electronics, radio theory and law. No morse code. No circuit drawings, etc. Geoff. -- Geoffrey S. Mendelson N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. |
#9
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Recommendation for electronics forums?
On 3/19/2011 9:28 PM Phil Allison spake thus:
"Geoffrey S. Mendelson" Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. ** That is in the same class as needing a pint of milk and so buying a cow. I agree, not a very good piece of advice. -- The phrase "jump the shark" itself jumped the shark about a decade ago. - Usenet |
#10
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Recommendation for electronics forums?
Hi David,
On 3/19/2011 6:39 PM, David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. I think you have to refine your overall goals/interests. There are many places you can find out "how to use an op amp" (or, "how an op amp works", etc.). But, what you *want* to use that op amp for is probably where you will get far more pertinent information/advice if you can refine your needs better. E.g., using an op amp to design a battery charger is different than using an op amp to buffer the pickup from an electric guitar or to implement a feedback loop in a robotic servo controller. A place that will give you "textbook" advice on how an op amp works (or can be applied) will leave you wondering, "OK, now how do I use that to ____________?" OTOH, a more targeted "forum" can tell you, "Why bother with an op amp? You can use a pair of transistors configured like ___________ to give you the results you need... with the following advantages: " Or, "If you use an op amp in that sort of application, you will need to add an external output stage to give you increased ___________. You can do that by _____________." Now, if the answer turns out to be "What, are you nuts? There ain't no such thing!", then I guess I can live with that ... |
#11
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" wrote: David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. You've got to be kidding. I know a lot of hams who don't even own a soldering iron. They ship their radios off for factory service, unlike 40 years ago. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#12
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Recommendation for electronics forums?
David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. Now, if the answer turns out to be "What, are you nuts? There ain't no such thing!", then I guess I can live with that ... news:sci.electronics.basics or news:sci.electronics.design are both good. You get more hand holding in the .basic group, but you see the same people from the .design group. They have more patience on the ..basic group which is intended to teach electronics, while the .design group is to trade ideas between professional designers. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#13
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. ** Only the " silent majority " ever did that .......... And none of them or the current few would have a clue about the use of op-amps in relation to audio. Wot a ****wit idea. Musta come from a radio ham. ..... Phil |
#14
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" Why not get your education from people who actually use the things ** Errr - since when do current radio hams use op-amps for anything ?? Most have no soldering irons or design knowledge at all. and follow an almost 100 year tradition of educating newcomers? ** New comers to ham radio generally get an " education " all right. The amount of effort is nothing like it used to be, you can earn a ham license in a weekend. ** Hmmm - that bodes well for giving new comers advice an all matters electronic..... You just need to answer 75% of 50 multiple choice questions corrent about basic electronics, radio theory and law. No morse code. No circuit drawings, etc. ** Same goes for the jokers you will find on the ham radio bands. Like this guy: Geoffrey S. Mendelson N3OWJ/4X1GM BTW The amateur bands have been damn near silent here in Australia for decades. The hobby is all but dead. CB radio, the internet and GSM phones have destroyed it. ..... Phil |
#15
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Recommendation for electronics forums?
Michael A. Terrell wrote:
You've got to be kidding. I know a lot of hams who don't even own a soldering iron. They ship their radios off for factory service, unlike 40 years ago. Totally irrelevant. I know a lot of people who can barely figure out how to put gasoline in their cars, but that does not mean there are is no one who knows how they work, and repair and "upgrade" their cars. It's like this group. You ask a question and you get answers. Most of them are not worth the paper they were never printed upon. You go to a web forum, you get the same results. You ask a bunch of hams and you get an answer. Not from all of them, but from one or two who know what they are talking about. Geoff. -- Geoffrey S. Mendelson N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. |
#16
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Recommendation for electronics forums?
I'm looking for an online electronics forum (web-based)
where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Amateur radio has largely become a plug 'n play hobby. Hams still build antennas, and sometimes high-power finals, but other than small projects and accessories, they mostly buy things. Don't expect to walk into a shack and find a home-brew receiver these days. One of the purposes in licensing amateur radio operators was to build a base of people with both theoretical and practical knowledge of electronics. It's not clear that it still does this. |
#17
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Recommendation for electronics forums?
Ideally, I'd like a forum where rank amateurs like me can post
questions that may be answered by "respected regulars" with lotsa knowledge on the subject. I think you have to refine your overall goals/interests. There are many places you can find out "how to use an op amp" (or, "how an op amp works", etc.). But, what you *want* to use that op amp for is probably where you will get far more pertinent information/advice if you can refine your needs better. E.g., using an op amp to design a battery charger is different than using an op amp to buffer the pickup from an electric guitar or to implement a feedback loop in a robotic servo controller. A place that will give you "textbook" advice on how an op amp works (or can be applied) will leave you wondering, "OK, now how do I use that to ______?" Not so! If you understand The Basic Rule in op-amp circuit design, you'll see that there is no difference among these applications. Nor will you be wondering how to do something. National Semiconductor had an on-line seminar "explaining" op-amp circuit design -- hostessed by a woman, of course -- and nowhere in it is The Basic Rule even hinted at. And Bob Pease had the nerve to tell me that my editing didn't improve the quality of his (or others') writing! |
#18
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Recommendation for electronics forums?
William Sommerwerck wrote:
Amateur radio has largely become a plug 'n play hobby. Hams still build antennas, and sometimes high-power finals, but other than small projects and accessories, they mostly buy things. Don't expect to walk into a shack and find a home-brew receiver these days. That's true. But you will find home brew (or at least kit) QRP rigs, audio and microphone amps, and similar items. Except in the UK, where one of the requirments for getting their "foundation" license is to have built something. One of the purposes in licensing amateur radio operators was to build a base of people with both theoretical and practical knowledge of electronics. It's not clear that it still does this. It still does. Like everyone who uses a computer, most people could never program their way out of a paper bag, there is a large population of hams who can't design or build anything. But there is still a small percentage, say 10% that do. In the US, that's about 60,000 or so. Enough that David should not have trouble finding one. The main objective of ham radio was to have a pool of radio operators ready in case of an emergency. In 1920 that meant being able to send and receive Morse code. In 2011, that means knowing how to set up and operate an FM two way radio, and how to take and pass messages correctly with little or no instuctions and not panicing. Geoff. -- Geoffrey S. Mendelson N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. |
#19
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Recommendation for electronics forums?
On 3/20/2011 5:39 AM, William Sommerwerck wrote:
Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. I think you have to refine your overall goals/interests. There are many places you can find out "how to use an op amp" (or, "how an op amp works", etc.). But, what you *want* to use that op amp for is probably where you will get far more pertinent information/advice if you can refine your needs better. E.g., using an op amp to design a battery charger is different than using an op amp to buffer the pickup from an electric guitar or to implement a feedback loop in a robotic servo controller. A place that will give you "textbook" advice on how an op amp works (or can be applied) will leave you wondering, "OK, now how do I use that to ______?" Not so! If you understand The Basic Rule in op-amp circuit design, you'll see that there is no difference among these applications. Nor will you be wondering how to do something. No, you only "get" to that point with experience. There are different design issues involved in each of the above applications. If you understand how an op amp works "in theory", you can look at an EXISTING circuit and suss out the functionality that the op amp is providing. But, that doesn't mean that you would be able to come up with the particular circuit topology that is avoiding some particular *real* (vs theoretical) limitation of that *particular* op amp and/or leveraging some particular characteristic thereof. If it could all be boiled down to a simple rule, then EVERYONE would be able to design perfect circuits "first time, every time" -- with/without SPICE. I want to design a 2KW, 2KV SMPS and use an op amp to compute the error term. Should be no different than designing a pickup for an electric guitar, right? Should I expect to have either/both of those designs on my desk, this afternoon, *completed*?? error |
#20
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Recommendation for electronics forums?
On 3/20/2011 5:31 AM, William Sommerwerck wrote:
I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Amateur radio has largely become a plug 'n play hobby. Hams still build antennas, and sometimes high-power finals, but other than small projects and accessories, they mostly buy things. Don't expect to walk into a shack and find a home-brew receiver these days. I think that is a matter of simple economics. You can buy finished, tested, "legit" product for less than you can purchase the components needed to build same. And, often, getting those components is tedious -- unless you have a business account to which you can add the order (or, buy THAT SORT OF COMPONENTS in big enough quantities that a sales rep will sample you a few pieces). Most electronic suppliers don't want to deal with small orders. And, the places that *will* have hefty markups (or don't carry the more exotic components). One of the purposes in licensing amateur radio operators was to build a base of people with both theoretical and practical knowledge of electronics. It's not clear that it still does this. I think dropping the code requirement was a clear acknowledgement of this. Now they're just trying to hold onto their frequency allocations. :-/ And, in practical terms, there are fewer and fewer things that even a motivated ham can design or repair in a modern household (contrast this with how "capable" he/she would be in a 1960's household) |
#21
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Recommendation for electronics forums?
Not so! If you understand The Basic Rule in op-amp circuit
design, you'll see that there is no difference among these applications. Nor will you be wondering how to do something. No, you only "get" to that point with experience. There are different design issues involved in each of the above applications. If you understand how an op amp works "in theory", you can look at an EXISTING circuit and suss out the functionality that the op amp is providing. But, that doesn't mean that you would be able to come up with the particular circuit topology that is avoiding some particular *real* (vs theoretical) limitation of that *particular* op amp and/or leveraging some particular characteristic thereof. If it could all be boiled down to a simple rule, then EVERYONE would be able to design perfect circuits "first time, every time" -- with/without SPICE. I want to design a 2KW, 2KV SMPS and use an op amp to compute the error term. Should be no different than designing a pickup for an electric guitar, right? Should I expect to have either/both of those designs on my desk, this afternoon, *completed*?? I probably overstated the case, but understanding Basic Principles can be a major leg-up to creating a workable design. A person who doesn't understand The Basic Rule of Op-Amp Circuit Operation is going to have a lot of trouble. I might add that, several years ago, I asked the English gentleman who worked with Bob Pease at National to tell me what that Rule was -- and bang, he said it right out, without any hints. |
#22
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Recommendation for electronics forums?
On Sun, 20 Mar 2011 05:09:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Locally, we have about 2800 licensed hams in the county, of which I would guess about 500 are at least semi-active, 100 regularly attend various club meetings, 50 bother to build things, and perhaps 4 are qualified to design anything useful. While it's possible to get some help with design and construction from ham radio, it really depends on whom you contact. This is the age of specialization. I can design and advise on some aspects of RF and repair. In other areas, I'm clueless. You would do best by finding a forum, blog, newsgroup, or mailing list that covers the specific area that you're interested in asking questions. Don't be fooled by the names or lack of traffic. There are often forums where most of the answers are by email from those that just don't want their names and advice subject to public scrutiny. For example, I've found that the LEAST useful forum for solving Apple computer related problems is Apple's own forums. Just post your question and see what happens. If you get a dozen one-line useless bad guesses, move on. As always, the quality of the answers depend heavily on the quality of the question. Without a clue as the nature of the question, vague answers, like this one, will be epidemic. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#23
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" wrote: Michael A. Terrell wrote: You've got to be kidding. I know a lot of hams who don't even own a soldering iron. They ship their radios off for factory service, unlike 40 years ago. Totally irrelevant. I know a lot of people who can barely figure out how to put gasoline in their cars, but that does not mean there are is no one who knows how they work, and repair and "upgrade" their cars. It's like this group. You ask a question and you get answers. Most of them are not worth the paper they were never printed upon. You go to a web forum, you get the same results. You ask a bunch of hams and you get an answer. Not from all of them, but from one or two who know what they are talking about. Right. Sure. Maybe in your small world. I recently went to the local ham radio club's hamfest. 99% of the items for sale were cheap chinese crap that is even cheaer on Ebay. the hams that knew what they were doing have either quit the hobby, or are now 'Silent Keys'. I saw more computer related items than radio, and the couple vendors with components had no one at their tables. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#24
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Recommendation for electronics forums?
On Sun, 20 Mar 2011 05:09:04 +0000, Geoffrey S. Mendelson wrote:
David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Not quite a web forum, but more personal. Geoff. Just renewed my ticket for the 2nd time. You might find a few hams that dabble in design but only because that's what they do for a living. The best way to learn besides OTJ training is to read. There isn't a day that passes that I don't read out of some old school books containing fundamental electronics. You need to understand why electronics work, and some mathematics involving calculating loads, current, power sine waves etc...first. I did it ass-backwards learning on the bench first using test equipment without knowing much about the fundamentals. -- Live Fast Die Young, Leave A Pretty Corpse |
#25
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" wrote: William Sommerwerck wrote: Amateur radio has largely become a plug 'n play hobby. Hams still build antennas, and sometimes high-power finals, but other than small projects and accessories, they mostly buy things. Don't expect to walk into a shack and find a home-brew receiver these days. That's true. But you will find home brew (or at least kit) QRP rigs, audio and microphone amps, and similar items. Except in the UK, where one of the requirments for getting their "foundation" license is to have built something. One of the purposes in licensing amateur radio operators was to build a base of people with both theoretical and practical knowledge of electronics. It's not clear that it still does this. It still does. Like everyone who uses a computer, most people could never program their way out of a paper bag, there is a large population of hams who can't design or build anything. But there is still a small percentage, say 10% that do. In the US, that's about 60,000 or so. Enough that David should not have trouble finding one. The main objective of ham radio was to have a pool of radio operators ready in case of an emergency. In 1920 that meant being able to send and receive Morse code. In 2011, that means knowing how to set up and operate an FM two way radio, and how to take and pass messages correctly with little or no instuctions and not panicing. More like 1975, not 2011 and this isn't Israel. There are plenty of commercial FM radios around, and all the county radios are digital. The only amateur related emergency gear is the club's HF station, near the county offices. They don't have a spare tower, or antennas that could be erected in a couple hours and there is no way in hell they could put up a replacement commercial digital radio base station or cell phone tower, even if they had months. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#26
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Recommendation for electronics forums?
D Yuniskis wrote: On 3/20/2011 5:39 AM, William Sommerwerck wrote: Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. I think you have to refine your overall goals/interests. There are many places you can find out "how to use an op amp" (or, "how an op amp works", etc.). But, what you *want* to use that op amp for is probably where you will get far more pertinent information/advice if you can refine your needs better. E.g., using an op amp to design a battery charger is different than using an op amp to buffer the pickup from an electric guitar or to implement a feedback loop in a robotic servo controller. A place that will give you "textbook" advice on how an op amp works (or can be applied) will leave you wondering, "OK, now how do I use that to ______?" Not so! If you understand The Basic Rule in op-amp circuit design, you'll see that there is no difference among these applications. Nor will you be wondering how to do something. No, you only "get" to that point with experience. There are different design issues involved in each of the above applications. If you understand how an op amp works "in theory", you can look at an EXISTING circuit and suss out the functionality that the op amp is providing. But, that doesn't mean that you would be able to come up with the particular circuit topology that is avoiding some particular *real* (vs theoretical) limitation of that *particular* op amp and/or leveraging some particular characteristic thereof. If it could all be boiled down to a simple rule, then EVERYONE would be able to design perfect circuits "first time, every time" -- with/without SPICE. I want to design a 2KW, 2KV SMPS and use an op amp to compute the error term. Should be no different than designing a pickup for an electric guitar, right? Wrong. A pickup for a guitar doesn't require a stable reference voltage to regulate it's output. Should I expect to have either/both of those designs on my desk, this afternoon, *completed*?? Look at national Semiconductor's 'Simple Switcher' line, or Linear's free Switchercad spice program and use ICs that are tailored to SMPS applications. If your opamp circuit takes too long to stabilize, you'll have an expensive failure and maybe a fire. Switchercad III can be downloaded he http://www.linear.com/software/ There is a Yahoo user group at: http://groups.yahoo.com/group/LTspice/ -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#27
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Recommendation for electronics forums?
On 3/20/2011 10:00 AM, William Sommerwerck wrote:
Not so! If you understand The Basic Rule in op-amp circuit design, you'll see that there is no difference among these applications. Nor will you be wondering how to do something. If it could all be boiled down to a simple rule, then EVERYONE would be able to design perfect circuits "first time, every time" -- with/without SPICE. I probably overstated the case, but understanding Basic Principles can be a major leg-up to creating a workable design. But, isn't that so of everything? : I enjoy watching folks "design by app-note" -- cutting and pasting together circuit fragments from various publications -- and wondering why their designs don't work. "Um, if you UNDERSTOOD what you had /designed/, you would understand why it WON'T work!" This is where The Trades have a leg up (in theory) on The Sciences. In the former, there is a hands-on learning process where you see the practical aspects of what you are learning *before* you are deemed "qualified" to practice that skill. In the latter, you get an abstract exposure to things (to be fair, often a wider range of "things" since "paper is cheap") but aren't qualified to use *any* of them before you are "certified" (diploma-ed). : M Crichton's novels are typically based on this "lack of (full) experience" -- Man having "getting" technology before he has "earned" it (i.e., has the wisdom to know how to *use* it). |
#28
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Recommendation for electronics forums?
On 3/20/2011 10:18 AM, Jeff Liebermann wrote:
On Sun, 20 Mar 2011 05:09:04 +0000 (UTC), "Geoffrey S. Mendelson" wrote: David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Locally, we have about 2800 licensed hams in the county, of which I would guess about 500 are at least semi-active, 100 regularly attend various club meetings, 50 bother to build things, and perhaps 4 are qualified to design anything useful. Expressed in your characteristic "dry" manner... : But, illustrates the point, well. Yet, doesn't say how accessible those "4" are nor where their interests lie. E.g., you would be hard-pressed to get me to help you design an audio amp out of discretes -- but, could probably keep me obsessed with trying to cut power consumption by half a milliwatt on a battery powered device! (and I'm a *helpful* soul ;-) A lot also depends on how dense that population of "experts" is, as well. E.g., our county is 9,200 sq mi with a population of just over 1,000,000. So, 90 people / sq mile. *If* we have those 2800 hams, here (no idea), that would be one ham for every 4 sq mi. That can make accessing that "expert" a bit problematic (I find learning is usually faster "in person"). And, if the hams (and population, in general) are not evenly distributed throughout the county, it only gets worse (potentially). E.g., there are *no* electronic suppliers, here, within driving distance. The closest possible (overpriced) retailer is clear across town (and would never have the types of components that I am interested in). While it's possible to get some help with design and construction from ham radio, it really depends on whom you contact. This is the age of specialization. Exactly! The days of being able to keep a drawer full of transistors, diodes, resistors, etc. and hack together an amplifier -- or a logic gate (!) -- are long behind us. Sure, you can still do it, but there is no point. I can recall building 8 digit counters out of discretes with nixie displays... would I bother wasting my time on that *now*?? (though I *have* been sorely tempted to build a Difference Engine). I can design and advise on some aspects of RF and repair. In other areas, I'm clueless. You would do best by finding a forum, blog, newsgroup, or mailing list that covers the specific area that you're interested in asking questions. Don't Agreed. ------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ be fooled by the names or lack of traffic. There are often forums where most of the answers are by email from those that just don't want their names and advice subject to public scrutiny. For example, I've found that the LEAST useful forum for solving Apple computer related problems is Apple's own forums. Just post your question and see what happens. If you get a dozen one-line useless bad guesses, move on. As always, the quality of the answers depend heavily on the quality of the question. Without a clue as the nature of the question, vague answers, like this one, will be epidemic. Wear rubber soled shoes, remove all jewelry, keep one hand in your pocket and *play*! It's not *chemistry* where you have to worry about losing eyebrows or other body parts when you make a mistake : All you have to lose is a little *money*! (and, depending on what you are playing with, many devices nowadays can take a LOT of abuse -- short circuit protection, etc. -- so you don't have to worry about replacing components every two ohnoseconds!) |
#29
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Recommendation for electronics forums?
Jeff Liebermann wrote:
On Sun, 20 Mar 2011 05:09:04 +0000 (UTC), "Geoffrey S. Mendelson" wrote: David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Locally, we have about 2800 licensed hams in the county, of which I would guess about 500 are at least semi-active, 100 regularly attend various club meetings, 50 bother to build things, and perhaps 4 are qualified to design anything useful. While it's possible to get some help with design and construction from ham radio, it really depends on whom you contact. Valid point, although I think you exaggerate a bit. Now, give those same numbers for the denizens of sci.electronics.repair. Maybe two numbers, with and without the profuse few who insist on pushing the SNR toward zero. I'd also like to hear your estimate of the percentage that even attempt to add USEFUL new information that helps answer the original question. Percentages by post will be different than percentage by author. And the percentage that just want to argue for the sake of arguing, name calling, backstabbing, "hey look how smart I think I am", etc. On any subject, it's important to ask someone who knows what he's talking about. Unfortunately, there are precious few of them. Most get drowned out by the multitude. Some of them ARE hams. -.- This is the age of specialization. I can design and advise on some aspects of RF and repair. In other areas, I'm clueless. You would do best by finding a forum, blog, newsgroup, or mailing list that covers the specific area that you're interested in asking questions. Don't be fooled by the names or lack of traffic. There are often forums where most of the answers are by email from those that just don't want their names and advice subject to public scrutiny. For example, I've found that the LEAST useful forum for solving Apple computer related problems is Apple's own forums. Just post your question and see what happens. If you get a dozen one-line useless bad guesses, move on. As always, the quality of the answers depend heavily on the quality of the question. Without a clue as the nature of the question, vague answers, like this one, will be epidemic. |
#30
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Recommendation for electronics forums?
On Sun, 20 Mar 2011 13:21:16 -0400, Michael A. Terrell wrote:
"Geoffrey S. Mendelson" wrote: Michael A. Terrell wrote: You've got to be kidding. I know a lot of hams who don't even own a soldering iron. They ship their radios off for factory service, unlike 40 years ago. Totally irrelevant. I know a lot of people who can barely figure out how to put gasoline in their cars, but that does not mean there are is no one who knows how they work, and repair and "upgrade" their cars. It's like this group. You ask a question and you get answers. Most of them are not worth the paper they were never printed upon. You go to a web forum, you get the same results. You ask a bunch of hams and you get an answer. Not from all of them, but from one or two who know what they are talking about. Right. Sure. Maybe in your small world. I recently went to the local ham radio club's hamfest. 99% of the items for sale were cheap chinese crap that is even cheaer on Ebay. the hams that knew what they were doing have either quit the hobby, or are now 'Silent Keys'. I saw more computer related items than radio, and the couple vendors with components had no one at their tables. When a few of us used to go in on a table at a hamfest we'd go dig in the attic or basement for a bunch of junk to sell. I used to go to Dayton Oh every year but that started being a joke. Most junk and computers. A few vendors from Kenwood, Yaesu, Alinco, MFD etc.. Not like it was 20 years ago. -- Live Fast Die Young, Leave A Pretty Corpse |
#31
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Recommendation for electronics forums?
Michael A. Terrell wrote:
More like 1975, not 2011 and this isn't Israel. Actually that's the US, and not here. In Israel there are 600 or so licensed hams, with about 250 in the IARC. With an almost 100% draft/national service, there is no need for hams as emergency communications. There were about 50 to 100 more two years ago, but the government sent out bills to renew the licenses and they decided it was not worth the money. There are plenty of radios in the government and IDF (military) and between previous experience in the military, annual reserve duty, and volunteer units (such as the border police, etc) there is absolutely no need for hams. The other big privleges/service the hams did was phone patches, which have been obsolete since 1997 when the price of international calls became cheaper than cross country ones and cell phones became cheap. In fact the IARC decided to do a drill this year just to do one, and they scheduled on the sabbath, which meant that 99% of the hams in Jerusalem and environment would not participate. It was like the ARRL scheduling a nationwide emergency drill without Maryland, Virgina, DC and so on. There are plenty of commercial FM radios around, and all the county radios are digital. The only amateur related emergency gear is the club's HF station, near the county offices. They don't have a spare tower, or antennas that could be erected in a couple hours and there is no way in hell they could put up a replacement commercial digital radio base station or cell phone tower, even if they had months. They don't need one. The ARRL's purpose in these drills is to do "health and welfare" messages e.g. "your aunt Matilda's ok in a shelter, but her house washed away". This is to offload that work from NGOs like the Red Cross and Salvation Army, so they can provide relief services. There also is no need to replace commercial digital radio base stations or cell phone towers, etc. There are plenty of people in the world who can do that, once the dust settles they will. It's the first few days that are critical. If things work properly, then the hams come in provide communications in the background for the "victims" without getting in the way. I know the hams here could not do it, and the ones that could would be back with their reserve units anyway. but here ham radio has never been much more than a hobby. Going back to David's question, I pointed out ham radio because he could use it to connect with someone who did know what he wanted and would be willing to help him. Someone pooh-poohed the idea because they wanted one to one instruction, which they would not of gotten from a web forum, which was the original request. It all comes down to expecting that someone who actually knows op-amps and is willing to answer questions about them is going to spend their time looking for and answering questions on a web forum. 99% of the questions asked on web forums are so basic that they are a waste of time to answer and the self proclaimed experts are unable to answer even those. BTW, did Don Lancaster ever update his "OP Amp Cookbook"? Geoff. -- Geoffrey S. Mendelson N3OWJ/4X1GM Those who cannot remember the past are condemned to misquote it. |
#32
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Recommendation for electronics forums?
"Geoffrey S. Mendelson" wrote: Michael A. Terrell wrote: More like 1975, not 2011 and this isn't Israel. Actually that's the US, and not here. In Israel there are 600 or so licensed hams, with about 250 in the IARC. With an almost 100% draft/national service, there is no need for hams as emergency communications. There were about 50 to 100 more two years ago, but the government sent out bills to renew the licenses and they decided it was not worth the money. There are plenty of radios in the government and IDF (military) and between previous experience in the military, annual reserve duty, and volunteer units (such as the border police, etc) there is absolutely no need for hams. The other big privleges/service the hams did was phone patches, which have been obsolete since 1997 when the price of international calls became cheaper than cross country ones and cell phones became cheap. In fact the IARC decided to do a drill this year just to do one, and they scheduled on the sabbath, which meant that 99% of the hams in Jerusalem and environment would not participate. It was like the ARRL scheduling a nationwide emergency drill without Maryland, Virgina, DC and so on. There are plenty of commercial FM radios around, and all the county radios are digital. The only amateur related emergency gear is the club's HF station, near the county offices. They don't have a spare tower, or antennas that could be erected in a couple hours and there is no way in hell they could put up a replacement commercial digital radio base station or cell phone tower, even if they had months. They don't need one. The ARRL's purpose in these drills is to do "health and welfare" messages e.g. "your aunt Matilda's ok in a shelter, but her house washed away". This is to offload that work from NGOs like the Red Cross and Salvation Army, so they can provide relief services. There also is no need to replace commercial digital radio base stations or cell phone towers, etc. There are plenty of people in the world who can do that, once the dust settles they will. It's the first few days that are critical. During which no one can help. A lot of radio stations lost their generators of STLS during the last round of hurricanes in Central Florida. The only news was via SW, but those services are no longer broadcasting to the US. If things work properly, then the hams come in provide communications in the background for the "victims" without getting in the way. Few HF antennas survive a hurricane around here. Downed power lines and little fuel availible for generators. In some places, people with a working cable modem are the only outside communications, since the RR backbone is buried fiber optic and it covers large areas of the US. I know the hams here could not do it, and the ones that could would be back with their reserve units anyway. but here ham radio has never been much more than a hobby. Going back to David's question, I pointed out ham radio because he could use it to connect with someone who did know what he wanted and would be willing to help him. Someone pooh-poohed the idea because they wanted one to one instruction, which they would not of gotten from a web forum, which was the original request. It all comes down to expecting that someone who actually knows op-amps and is willing to answer questions about them is going to spend their time looking for and answering questions on a web forum. I posted links to the proper Usenet groups, a free spice program and a Yahoo support group. I still don't like the idea of using an opamp in a SMPS. 99% of the questions asked on web forums are so basic that they are a waste of time to answer and the self proclaimed experts are unable to answer even those. BTW, did Don Lancaster ever update his "OP Amp Cookbook"? Ask him. He posts on sci.electronics.design once in a while. His website is http://www.tinja.com He put a few of his books online a while back and posted links. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#33
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Recommendation for electronics forums?
Meat Plow wrote: On Sun, 20 Mar 2011 13:21:16 -0400, Michael A. Terrell wrote: "Geoffrey S. Mendelson" wrote: Michael A. Terrell wrote: You've got to be kidding. I know a lot of hams who don't even own a soldering iron. They ship their radios off for factory service, unlike 40 years ago. Totally irrelevant. I know a lot of people who can barely figure out how to put gasoline in their cars, but that does not mean there are is no one who knows how they work, and repair and "upgrade" their cars. It's like this group. You ask a question and you get answers. Most of them are not worth the paper they were never printed upon. You go to a web forum, you get the same results. You ask a bunch of hams and you get an answer. Not from all of them, but from one or two who know what they are talking about. Right. Sure. Maybe in your small world. I recently went to the local ham radio club's hamfest. 99% of the items for sale were cheap chinese crap that is even cheaer on Ebay. the hams that knew what they were doing have either quit the hobby, or are now 'Silent Keys'. I saw more computer related items than radio, and the couple vendors with components had no one at their tables. When a few of us used to go in on a table at a hamfest we'd go dig in the attic or basement for a bunch of junk to sell. I used to go to Dayton Oh every year but that started being a joke. Most junk and computers. A few vendors from Kenwood, Yaesu, Alinco, MFD etc.. Not like it was 20 years ago. I haven't been to the Dayton Hamvention in 25 years. Prior to that, I went almost every year, from the late '60s. I lived closer to Cincinnati, and hit about five hamfests each year, except while on active duty. The only hams in that area that knew electronics both worked for R.L. Drake in Miamisburg, and they frequently asked me for help. I repaired a lot of older ham gear, including some homebrew with no documentation. I also worked at Cincinnati Electronics on the PRC-77 manpack radio doing QA. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
#34
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Recommendation for electronics forums?
In Israel there are 600 or so licensed hams...
It's amazing there are ANY! |
#35
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Recommendation for electronics forums?
On Sun, 20 Mar 2011 14:47:36 -0800, David Nebenzahl wrote:
On 3/20/2011 1:10 AM Michael A. Terrell spake thus: David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) news:sci.electronics.basics or news:sci.electronics.design are both good. You get more hand holding in the .basic group, but you see the same people from the .design group. They have more patience on the .basic group which is intended to teach electronics, while the .design group is to trade ideas between professional designers. How did you miss that I specifically requested an online forum, not other Usenet newsgroups? It's right up there in the very first sentence I wrote, for chrissakes. Remember Dave, honey attracts more flies than vinegar -- Live Fast Die Young, Leave A Pretty Corpse |
#36
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Recommendation for electronics forums?
On 3/20/2011 1:10 AM Michael A. Terrell spake thus:
David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) news:sci.electronics.basics or news:sci.electronics.design are both good. You get more hand holding in the .basic group, but you see the same people from the .design group. They have more patience on the .basic group which is intended to teach electronics, while the .design group is to trade ideas between professional designers. How did you miss that I specifically requested an online forum, not other Usenet newsgroups? It's right up there in the very first sentence I wrote, for chrissakes. -- The phrase "jump the shark" itself jumped the shark about a decade ago. - Usenet |
#37
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Recommendation for electronics forums?
Hi David,
On 3/20/2011 4:01 PM, David Nebenzahl wrote: On 3/19/2011 9:09 PM Geoffrey S. Mendelson spake thus: David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Not quite a web forum, but more personal. Interesting suggestion, but highly impractical for me for several reasons. First of all, it would require a whole 'nother pursuit--getting the license AND acquiring/building/setting up a radio rig, which is definitely *not* what I'm the least bit interested in at this point. Getting a "Technician" license would require about an evening of your time -- plus travel to/from exam. And, I think, $6 (?) exam fee. No need to set up a radio, etc. Just like getting a driver's license doesn't require you to own -- or even DRIVE! -- a car. [But, I understand your point...] Then there's the problem of the medium. Web fora are perfect for my porpoises: I can easily send text and images, and receive the same. With radio, I'd have to exhaustively describe every little detail of what I'm trying to do. And unless I had some kind of radio-fax setup, whereby I could transmit images (and images of extremely ****ty quality at that), how would I exchange schematics with other hams? Email? or, ironically, posting them on the Web? You have access to all the same media with a ham license. The point is, you (can) "hang with a different crowd". Hopefully one that, at a minimum, knows that electrical power is measured in Watts, inductance is expressed in Henries and that a current of 2 amps flowing through a resistance of 3 ohms develops a potential of 6 volts. I.e., questions that separate the "men" from the... um... I forget... [I think that about sums up the Technician Class, eh? : ] A good bit of the license information deals with *regulations* and conduct/expectations/responsibility/etc. Sorry, not a good suggestion. I will say, though, that I do have a copy of the ARRL Handbook (1991) which has been quite useful, if a bit out of date. I don't think the license itself will buy you anything towards your goal (though, as an aside, you might consider downloading the question pools for the various license classes and wading through the "technical" questions /cold/ to get a feel for just how much you actually already *know*. This could be encouraging -- or discouraging -- to you.) Rather, the real value is getting you exposed to that sort of person. Sort of like hanging around a sports bar (instead of a LIBRARY) if you are interested in learning about sports... (google: technician ham questions) |
#38
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Recommendation for electronics forums?
"Dave M" wrote in message
... David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. Now, if the answer turns out to be "What, are you nuts? There ain't no such thing!", then I guess I can live with that ... Give this one a try... Everything there from dummies to experts. http://www.electro-tech-online.com/ -- David dgminala at mediacombb dot net http://www.eevblog.com/forum/ The EEVblog is headed by Dave Jones, an EE in Australia. The forum is for beginners and experienced EE's and anyone interested in electronics design and hardware (test equipment, etc). Mark Z. |
#39
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Recommendation for electronics forums?
On 3/19/2011 11:51 PM D Yuniskis spake thus:
On 3/19/2011 6:39 PM, David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Don't get me wrong: I love, and usually prefer, Usenet. But I'm trying to educate myself here, am working on a project, and a web forum that allows one to post pictures would be better for my purposes. At least I'd like to try it. (The subject of my current research is the ins and outs of op amps.) Ideally, I'd like a forum where rank amateurs like me can post questions that may be answered by "respected regulars" with lotsa knowledge on the subject. I think you have to refine your overall goals/interests. There are many places you can find out "how to use an op amp" (or, "how an op amp works", etc.). But, what you *want* to use that op amp for is probably where you will get far more pertinent information/advice if you can refine your needs better. E.g., using an op amp to design a battery charger is different than using an op amp to buffer the pickup from an electric guitar or to implement a feedback loop in a robotic servo controller. Be that as it may, I went ahead and joined the first forum that was suggested here (Electro-Tech Online, http://www.electro-tech-online.com) and whaddya know, I got answers--pretty good ones--within an hour that allowed me to get parts of my project working. Maybe it's not the definitive, be-all and end-all of understanding op amp operation that you seem to be suggesting, but that isn't what I asked for anyhow. I'm just trying to muddle through at this point. Actually, I have a pretty good textbook which probably has all the answers I need, if I can only understand them: Albert Malvino's /Electronic Principles/ (actually fished out of a dumpster!). It's extremely well-written and explains all about op amp operation, including the four feedback configurations (SP/SS/PP/PS), calculating gain and impedance, and various op amp applications. Now if I can only get over having to deal with the math (ugh!) ... -- The phrase "jump the shark" itself jumped the shark about a decade ago. - Usenet |
#40
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Recommendation for electronics forums?
On 3/19/2011 9:09 PM Geoffrey S. Mendelson spake thus:
David Nebenzahl wrote: I'm looking for an online electronics forum (web-based) where I can post some questions. Get a ham license. Then you can find people who actively design and build things, like to talk about them and would gladly help you. Not quite a web forum, but more personal. Interesting suggestion, but highly impractical for me for several reasons. First of all, it would require a whole 'nother pursuit--getting the license AND acquiring/building/setting up a radio rig, which is definitely *not* what I'm the least bit interested in at this point. Then there's the problem of the medium. Web fora are perfect for my porpoises: I can easily send text and images, and receive the same. With radio, I'd have to exhaustively describe every little detail of what I'm trying to do. And unless I had some kind of radio-fax setup, whereby I could transmit images (and images of extremely ****ty quality at that), how would I exchange schematics with other hams? Email? or, ironically, posting them on the Web? Sorry, not a good suggestion. I will say, though, that I do have a copy of the ARRL Handbook (1991) which has been quite useful, if a bit out of date. -- The phrase "jump the shark" itself jumped the shark about a decade ago. - Usenet |
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