Recommendation for electronics forums?
David Nebenzahl
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
Dave M
> 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
Smitty Two
David Nebenzahl <nob...@but.us.chickens> wrote:
> The subject of my current research is the ins and
> outs of op amps.
A little pun, there?
Rich Webb
<nob...@but.us.chickens> 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
Michael A. Terrell
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.
Geoffrey S. Mendelson
> 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.
Phil Allison
"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
David Nebenzahl
I agree, not a very good piece of advice.
Geoffrey S. Mendelson
>
> 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.
D Yuniskis
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 _____________."
Michael A. Terrell
"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.
Michael A. Terrell
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.
Phil Allison
"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 fuckwit idea.
Musta come from a radio ham.
.... Phil
Phil Allison
"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
Geoffrey S. Mendelson
> 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.
William Sommerwerck
>> 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.
William Sommerwerck
>> 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!
Geoffrey S. Mendelson
> 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.
D Yuniskis
>>> 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
D Yuniskis
>>> 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)
William Sommerwerck
>> 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.
Jeff Liebermann
<g...@mendelson.com> 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 je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Michael A. Terrell
"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.
Meat Plow
> 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
Michael A. Terrell
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.
Michael A. Terrell
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 here:
http://www.linear.com/software/
There is a Yahoo user group at:
http://groups.yahoo.com/group/LTspice/
D Yuniskis
>>> 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.
>>
>> EVERYONE would be able to design perfect circuits "first
>> time, every time" -- with/without SPICE.
>
> 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).
D Yuniskis
> On Sun, 20 Mar 2011 05:09:04 +0000 (UTC), "Geoffrey S. Mendelson"
> <g...@mendelson.com> 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!)
mike
> On Sun, 20 Mar 2011 05:09:04 +0000 (UTC), "Geoffrey S. Mendelson"
> <g...@mendelson.com> 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.
-.-
Meat Plow
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.
Geoffrey S. Mendelson
> 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"?
Michael A. Terrell
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.
Michael A. Terrell
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.
William Sommerwerck
It's amazing there are ANY!
David Nebenzahl
> 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
David Nebenzahl
> 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!) ...
Meat Plow
Remember Dave, honey attracts more flies than vinegar :)
David Nebenzahl
> 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 shitty 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.
David Nebenzahl
> 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.
>>>
>>> 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 :)
I'll be sure to remember that next time I want to attract a bunch of flies!
D Yuniskis
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 shitty 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)
Mark Zacharias
news:nImdnQx-34AyzBjQ...@giganews.com...
> David Nebenzahl wrote:
>> I'm looking for an online electronics forum (web-based) where I can
>> post some questions.
>>
>> 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.)
>>
>> questions that may be answered by "respected regulars" with lotsa
>> knowledge on the subject.
>>
>> 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
>
>
>
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.
D Yuniskis
On 3/20/2011 3:54 PM, David Nebenzahl wrote:
> 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.
>>
>> 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.
>
> 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
Great! Then you're set -- for now.
> definitive, be-all and end-all of understanding op amp operation that
No, quite the contrary. If you know *everything* about op amps,
then there is no difference between applications -- because you
already know all the little details that differentiate one
type of application from another.
My point was, if you find a group that is dealing with the same
types of applications that you are wanting to address, then they
will have already tweaked the "oversimplification" of what an
op amp is by appending "... except, you have to do ________ when
you use it *this* way _______" to that description. I.e., they
will have highlighted the details that are important in *that*
type of application (e.g., if you are running with a single
supply instead of balanced supplies, needing more voltage
compliance in your output than the op amp can provide, etc.)
Most of "design" is figuring out which details to *ignore* and
which to *pursue*. A group of folks working on similar
applications will have already sorted that out for you.
[I recall designing (passive) speaker crossover networks with
a friend at school. He always had "50 ..." as his expressions.
I finally asked him where the heck he kept coming up with this
"50"?? Ans: 2 * pi * 8 ohms (more or less)
D'oh!
> 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!) ...
I started with Senturia & Wedlock's _Electronic Circuits and
Applications_ (and, before that, just reading data sheets). It
was one of those "good" books that predated the "sold by the
pound" trend that seems to have infected "modern" writing :<
(though it was $20+ about 35 years ago!)
There also were "Made Simple" books aeons ago (When Dinosaurs
Walked the Earth). These were the precursors of the "For Dummies"
books -- but infinitely more intense! Highly condensed but
very good to get exposed to a lot in very few pages.
(e.g., "Electronics Made Simple")
Jeff Liebermann
<not.goi...@seen.com> wrote:
>On 3/20/2011 10:18 AM, Jeff Liebermann wrote:
>> On Sun, 20 Mar 2011 05:09:04 +0000 (UTC), "Geoffrey S. Mendelson"
>> <g...@mendelson.com> 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... :>
I try not to get excited about such things.
>But, illustrates the point, well. Yet, doesn't say how accessible
>those "4" are nor where their interests lie.
Actually, very accessible, if they're interested. We have a local
startup, Elecraft, that makes ham radio kits and accessories. Most of
the qualified hams in the area are now working for them.
<http://www.elecraft.com>
There's not much design work being done locally, but the engineers and
techs certainly know how the radios operate.
>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 ;-)
I have a similar problem. When I was still designing electronics, the
major obsession was reducing the cost. At that time, it meant
reducing the component count. If you get my attention, I can waste
enormous amounts of time, on futile exercises in component count
reduction. Same with unusual ways to implement simple things.
>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").
You can get a fair idea of the number of hams by diving into the FCC
ULS database and searching for counts by your local zip codes.
<http://wireless2.fcc.gov/UlsApp/UlsSearch/searchAmateur.jsp>
For 95005 (Ben Lomond, CA), it shows 61 licenses. Unfortunately, the
FCC updates the data perhaps every 10 years, so some hams that have
moved out or died are still listed.
>And, if the hams (and population, in general) are not evenly
>distributed throughout the county, it only gets worse (potentially).
Worse, most hams seem to live in post office boxes.
>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).
We have one local supplier (other than Radio Shock). They're
expensive, but not outrageous.
<http://www.santacruzelectronics.com>
>> 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.
Yep. Just finding the part in my mess is difficult. However, I do
have a fairly good collection of 1980's vintage discrete parts, which
are useful for raising the dead and repairing the antiques.
One problem with specialization is that it tends to create some rather
bizarre implementations. I once reverse engineered a microprocessor
design that could have been replaced by a quad op amp.
>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).
Hint: I never build or design anything that I can't sell or turn into
a sellable product. When I do build something for myself, I usually
build 3 to 5 extras, to sell to friends and recover my expenses.
Expertise in PCB layout is a must.
Note that it's still possible to have fun with electronics:
"How to blow up a microwave"
<http://www.youtube.com/watch?v=V9Gn0auLFUA>
Jeff Liebermann
>> 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.
I'm fairly sure about the 2800 hams in Santa Cruz County. The other
numbers are from many years of experience dealing with exactly the
issues that were mentioned. For example, the local electronics dealer
(Santa Cruz Electronics) often sends me customers who need some
expertise beyond what could be provided by the counter sales person,
but not so much that it would require a consulting contract. Much of
the stuff people want designed already exists. Other time, I end up
building some abomination for yet another get rich quick scheme.
Sometimes, I have to ask for help (i.e. I'm a lousy programmer), so I
have a clue as to how many locals are available and able to help. Of
course, since I'm a member of both SCZ County radio clubs, I know how
many of those are hams. My numbers might be off perhaps +/- 25%, but
not much more.
>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.
Well, if you mean topic drift, you're discussing the problem with the
chief culprit. If the original question is boring or of little
interest, I simply change the topic. If the OP wants his question
answered, he can simply rephrase it so that it's more interesting and
less boring.
>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.
That's easy. Just grep through the answers and see how many answers
supply calculations, numbers, references, and specifics. It won't be
many, but if you look hard, you may find some specific answers. URL's
don't count because most people don't explain why the URL should be
read.
In my case, I always try to add something useful to my answers. It
may not answer the original question, but it should be at least
interesting.
>Percentages by post will be different than percentage
>by author.
True. Quantity is a bad substitute for quality. Just ignore the
quantity of my words and postings.
>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.
That would be 100%. I doubt that everyone is interested in helping
the OP as much as grandstanding, ego inflation, or some kind of power
trip. It's a futile effort, but it's still commonly practiced. My
motivation varies radically by the day. For example, todays endless
drivel is justified by my procrastinating on working on my income
taxes. Other days, I'm don't have a clue about the original question,
but am sufficiently interested in the topic to do the necessary
research on the topic, and present a passable summary of what I've
found. In rare cases, I may have some experience or knowledge about
the topic, and deign to pontificate about it. Whatever works.
>On any subject, it's important to ask someone who knows what he's talking
>about.
Not really. I ask very few questions. My last attempt resulted in
demonstrating how I can ignore the obvious by installing several
polarized capacitors backwards.
<http://802.11junk.com/jeffl/crud/GX520-bad-caps.jpg>
Even so, there were plenty of wrong answers supplied by various people
trying to be helpful. In most cases, I can eliminate the clueless by
simply looking at the writing style. No numbers means no clue. One
line answers means no thinking was involved in crafting the answer.
Pontifications without substantiation means that they're not really
certain about their answer or their abilities. I don't even bother
with RTFM type answers. However, I'm perfectly willing to grovel
through the garbage for an answer and NEVER pass judgment on the
author. The reason dates back to my introduction to usenet, where I
managed to accidentally insult a well known expert, who didn't have
the time or interest to offer more than a general clue.
Incidentally, I've seen more wrong answers by established experts, who
are either too much in a hurry to supply a complete answer, or make
assumptions that the reader may not be able to catch.
>Unfortunately, there are precious few of them.
On the contrary. Everyone is an expert on something. Where the
problems start are when they go out of their area of expertise. The
recent discussions on nuclear reactors in various forums is a great
example. Most of those posting are perfectly competent in their areas
of expertise, but rather marginal when discussing nuclear power.
Similarly, the amazing number of climate experts in the global warming
discussion should make one wonder how there can possibly be so many
climate experts in a field that didn't really exist more than perhaps
10 years ago.
Incidentally, ever notice that the more insignificant the question,
the more answers are supplied. Really well written and important
questions, rarely get any attention.
>Most get drowned out by the multitude.
At the bottom of every dumpster is a diamond. It's yours if you're
willing to dig through the muck.
>Some of them ARE hams.
Sure. However, the typical 10 minute monologue on 80 meters doesn't
offer much of an endorsement.
Jeff Liebermann
<g...@mendelson.com> wrote:
>BTW, did Don Lancaster ever update his "OP Amp Cookbook"?
>Geoff.
As far as I can determine from Googling, the 3rd and last edition was
published in 1986.
Hmmm... that's odd. It's not listed:
<http://www.tinaja.com/books/bkdons.asp>
D Yuniskis
On 3/20/2011 4:11 PM, Jeff Liebermann wrote:
[attributions elided]
>> But, illustrates the point, well. Yet, doesn't say how accessible
>> those "4" are nor where their interests lie.
>
> Actually, very accessible, if they're interested. We have a local
-----------------------------^^^^^^^^^^^^^^^^^^^^^
I seem to recall making comments to that effect ;-)
> startup, Elecraft, that makes ham radio kits and accessories. Most of
> the qualified hams in the area are now working for them.
> <http://www.elecraft.com>
> There's not much design work being done locally, but the engineers and
> techs certainly know how the radios operate.
>
>> 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 ;-)
>
> I have a similar problem. When I was still designing electronics, the
> major obsession was reducing the cost. At that time, it meant
> reducing the component count. If you get my attention, I can waste
> enormous amounts of time, on futile exercises in component count
> reduction. Same with unusual ways to implement simple things.
In the mid 70's, I had to design a replacement "front panel"
for a Nova (2 or 3... I can't recall) minicomputer. This is
the vintage equipment where you "bit-switched" (toggled) data
into memory (real core!), forced a value into the program counter
and then hit "run".
The actual front panel was bulky -- all those "bats" on the front
panel switches plus plastic molding, etc. Since the machine
only had to do certain very fixed things (I guess it qualified as
an "embedded system" -- even though the processor was the size
of a small washing machine!), it was silly to ship the bulky
panel with the unit.
The panel worked by driving values onto an "open collector" bus
and stroking control lines. So, any replacement "front panel"
needed logic to interface to a few dedicated switches (reset,
IPL, etc.), decode logic to drive the right values onto the
bus, some crude timing (remember, we are emulating things that
a human being does "by hand") and, of course, open collector
drivers to actually *drive* the bus.
I ended up with a design that used a 7 segment decoder (!)
wired in a bizarre way to (coincidentally) get the right
values onto the bus based on an examination of the switch
states connected to the BCD inputs thereof. (this predates
FPGAs, GALs and even *PLAs*!)
My boss was impressed -- but too scared to risk such a bizarre
implementation: "How will anyone ever know how it is *supposed*
to work?" (to me, that was pretty obvious: the devices work
just like any other devices... read the data sheet!)
>> 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").
>
> You can get a fair idea of the number of hams by diving into the FCC
> ULS database and searching for counts by your local zip codes.
> <http://wireless2.fcc.gov/UlsApp/UlsSearch/searchAmateur.jsp>
> For 95005 (Ben Lomond, CA), it shows 61 licenses. Unfortunately, the
> FCC updates the data perhaps every 10 years, so some hams that have
> moved out or died are still listed.
Lots of ZIP codes in 9000 square miles. I'll leave that as an
exercise for the student...
>> And, if the hams (and population, in general) are not evenly
>> distributed throughout the county, it only gets worse (potentially).
>
> Worse, most hams seem to live in post office boxes.
Yes. Though, if you're smart, you use a non-USPS "p.o.box"
>> 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).
>
> We have one local supplier (other than Radio Shock). They're
> expensive, but not outrageous.
> <http://www.santacruzelectronics.com>
I bought some small lytic's for ~$2/ea. C'mon, now... (then
they complain when folks buy mail-order from firms out-of-state!)
>>> 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.
>
> Yep. Just finding the part in my mess is difficult. However, I do
> have a fairly good collection of 1980's vintage discrete parts, which
> are useful for raising the dead and repairing the antiques.
I find more use for *hardware* (screws, connectors, etc.) than
"components". As I get older, time is more valuable to me than
"mundane cost saving experiences" (though I replaced a power
cord on a make-up mirror, yesterday... can you spell "mindless"?).
So, if anything "complex" dies, I typically just recycle it and
replace it (I collect "spares" of lots of things so this often
just means taking another off the shelf). To invest any serious
amount of time, it either has to be a really interesting problem
*or* something of considerable value (including "irreplaceable")
> One problem with specialization is that it tends to create some rather
> bizarre implementations. I once reverse engineered a microprocessor
> design that could have been replaced by a quad op amp.
I had a colleague design a state machine for an LCD controller
using a 64KB EPROM (back when a 64K EPROM was *big*!). When I
dumped the EPROM, I discovered it implemented a simple logic
function of *3* variables (despite all the "inputs" that
were wired to it's address lines). I.e., it could have been
replaced by a quad _______ or, perhaps, a dual AOI.
<shrug> He didn't care. On to the next design...
>> 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).
>
> Hint: I never build or design anything that I can't sell or turn into
> a sellable product. When I do build something for myself, I usually
> build 3 to 5 extras, to sell to friends and recover my expenses.
> Expertise in PCB layout is a must.
I tend to take the *opposite* approach. I like building "one of
a kind" pieces. Especially as gifts. I.e., the value of the
gift is the fact that it is unique. And, sufficiently expensive
to undertake "duplication" that it would need to have a significant
number of "buyers" to make it worthwhile (i.e., it is not
economically feasible for a "competitor" to make something like
this, thereby rendering the uniqueness of the gift meaningless).
Difference Engine would be cool as it would require lots of
*mechanical* skill/assembly/fabrication -- not something you
could just run off a set of Gerbers!
Anything that I design lately that would appeal to others
I just release as "open source" (hardware and software) so
anyone who wants to invest the time/energy can copy at will.
> Note that it's still possible to have fun with electronics:
> "How to blow up a microwave"
> <http://www.youtube.com/watch?v=V9Gn0auLFUA>
I've thought about setting up a tesla coil proximate to
the hummingbird feeder to zap the *woodpeckers* when they
try to use it. But, it would be hard to control where
the discharge went... :<
(I wonder what burnt woodpecker smells like?)
Michael A. Terrell
My suggestion still stands. Online forums drop like flies, so I've
stopped even trying to find one that's useful. Do whatever you like.
JW
<mike.t...@earthlink.net> wrote in Message id:
<z5idnSkllaUR4hjQ...@earthlink.com>:
>
>Smitty Two wrote:
>>
>> In article <4d854cd2$0$2434$8226...@news.adtechcomputers.com>,
>> David Nebenzahl <nob...@but.us.chickens> 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...
I dunno, but then again I may be biased.
Michael A. Terrell
I figured that you were a little off center. :)
Franc Zabkar
<nob...@but.us.chickens> put finger to keyboard and composed:
>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.
Here in Australia most ISPs offer free web space to their users. I use
my web space to post pictures and other binary data. Is that an option
for you?
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
David Nebenzahl
> On Sat, 19 Mar 2011 17:39:54 -0800, David Nebenzahl
> <nob...@but.us.chickens> put finger to keyboard and composed:
>
>> 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.
>
> Here in Australia most ISPs offer free web space to their users. I use
> my web space to post pictures and other binary data. Is that an option
> for you?
It's an option I'm already using. Well, not through my ISP, but using
one of the dozens of free photo hosting sites out there. In fact, the
forum I'm using (see below) doesn't let me post pictures directly, so I
have to first post them to a hosting site, then give a link to the
picture in the forum posting. A little cumbersome, but not too bad.
The thing I like about the web forums (I'm using Electro-Tech now, as
suggested above) is that you can post pictures *in your message*. What a
concept! So rather than dicking around with "binary" newsgroups (which I
don't use anymore since I stopped downloading pron), I can post
schematics, etc., right in the message.
As I said, I still prefer Usenet for most online communication. But
these newfangled Web thingies sure have their good points.
--
The current state of literacy in our advanced civilization:
yo
wassup
nuttin
wan2 hang
k
where
here
k
l8tr
by
- from Usenet (what's *that*?)
Mark Zenier
Jeff Liebermann <je...@cruzio.com> wrote:
>On Sun, 20 Mar 2011 19:39:12 +0000 (UTC), "Geoffrey S. Mendelson"
><g...@mendelson.com> wrote:
>
>>BTW, did Don Lancaster ever update his "OP Amp Cookbook"?
>>Geoff.
>
>As far as I can determine from Googling, the 3rd and last edition was
>published in 1986.
>
>Hmmm... that's odd. It's not listed:
><http://www.tinaja.com/books/bkdons.asp>
That's because Walter Jung wrote it.
Mark Zenier mze...@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)
Sofa Slug
> On 3/21/2011 1:10 PM Franc Zabkar spake thus:
>
>> On Sat, 19 Mar 2011 17:39:54 -0800, David Nebenzahl
>> <nob...@but.us.chickens> put finger to keyboard and composed:
>>
>>> I'm looking for an online electronics forum (web-based) where I can
>>> post some questions.
>>>
>
DutchForce is a good one: http://www.dutchforce.com/~eforum/index.php?
EdDataFix
I am into LCD repairs and have found info on parts and sources.
EdDataFix
Wiebe Cazemier
>> >
>> >Smitty Two wrote:
>> >>
>> >> In article <4d854cd2$0$2434$8226...@news.adtechcomputers.com>,
>> >> David Nebenzahl <nob...@but.us.chickens> 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...
>>
>> I dunno, but then again I may be biased.
>
>
> I figured that you were a little off center. :)
>
>
Now that's unfair feedback :)
Michael A. Terrell
Not if you're at unity gain... :)
Wiebe Cazemier
>> >> >>
>> >> >> > 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...
>> >>
>> >> I dunno, but then again I may be biased.
>> >
>> >
>> > I figured that you were a little off center. :)
>> >
>> >
>>
>> Now that's unfair feedback :)
>
>
> Not if you're at unity gain... :)
But then you'll run into oscillation
Michael A. Terrell
Everyone needs to exercise. :)
Wiebe Cazemier
>
> Wiebe Cazemier wrote:
>>
>> Michael A. Terrell 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...
>> >> >>
>> >> >> I dunno, but then again I may be biased.
>> >> >
>> >> >
>> >> > I figured that you were a little off center. :)
>> >> >
>> >> >
>> >>
>> >> Now that's unfair feedback :)
>> >
>> >
>> > Not if you're at unity gain... :)
>>
>> But then you'll run into oscillation
>
>
> Everyone needs to exercise. :)
To obtain a higher slew-rate?
Michael A. Terrell
Or just to keep from rusting, in place. :)
Wiebe Cazemier
>
> Wiebe Cazemier wrote:
>>
>> Michael A. Terrell wrote:
>>
>> >
>> > Wiebe Cazemier wrote:
>> >>
>> >> Michael A. Terrell 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...
>> >> >> >>
>> >> >> >> I dunno, but then again I may be biased.
>> >> >> >
>> >> >> >
>> >> >> > I figured that you were a little off center. :)
>> >> >> >
>> >> >> >
>> >> >>
>> >> >> Now that's unfair feedback :)
>> >> >
>> >> >
>> >> > Not if you're at unity gain... :)
>> >>
>> >> But then you'll run into oscillation
>> >
>> >
>> > Everyone needs to exercise. :)
>>
>> To obtain a higher slew-rate?
>
>
> Or just to keep from rusting, in place. :)
>
I've run out of bandwidth...
Michael A. Terrell
You need a wider pipe...
Wiebe Cazemier
>> >
>>
>> I've run out of bandwidth...
>
>
> You need a wider pipe...
>
>
That's what the plumber said...
Michael A. Terrell
The 'Watergate plumbers' used tape.
learn electronics
http://www.virtualelectronicsclub.com/
MJC
zayed...@gmail.com says...
> The Virtual Electronics Club Is established to support Engineers with creative and innovative ideas and build a unique electronics culture among their members to build and design electrical circuits. Virtual Electronics Club is the world's #1 source for sharing ideas on electronics, get news on electronics, interviews, electronics projects, videos, tool reviews and more!
> http://www.virtualelectronicsclub.com/
Mike.
Phoena Greene
"learn electronics" <zayed...@gmail.com> wrote in message
news:0757d068-cf53-4f28...@googlegroups.com...