Standard non-inverting opamp with a cap across + and - terminals...... Why?

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Can they continue to disapprove of Sloman?

Doesn't everybody?

But that brings up the point that crystal sets must have a ton of harmonic distortion for weak signals. I never noticed that as a kid.

John

Hi Michael,

I realize you might not have a lot of spare funds for such a trip, but lately they've made quite an effort to make it reasonably viable for those with physical limitations to still get around -- all the parking in front of the Hara Arena is reserved for those with handicapped permits and there's a scooter rental company on-site.

The average age of a ham radio operator these days is pushing 50, I suspect, so they've had to make such accomodations. I've been surprised at how many talking radios, SWR meters, etc. there are now -- a lot of blind or low-sighted people seem to really enjoy the hobby.

---Joel

That's probably because you listened to rock & roll all the time and it was always above 26mV.

You couldn't hear the distortion, for the static! ;-)

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As long as you fail to appreciate that the 26mV is a way of referring the reader back to the Ebers-Moll relationship, I've still got some work left to do.

-- Bill Sloman, Nijmegen

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Weasel. Moron. That's not what you said. You flat said that there is no rectification below 26 mV RF input. You were called on it by lots of people who know better.

But "work to do"? When was the last time you did any work?

John

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Does collecting his welfare check still count?

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Like I just said, there's less, and as you go much below 26mV, a lot less. As I said, it's hard enough to get you guys to read short declarative sentences without raising the level of difficulty with qualiflying clauses.

They also claimed that the critical difference between bipolar input amplifiers and MOSFET input amplifers is the presence (or absence) of a bipolar diode junction at the input, where it is purely a matter of the transconductance of the input, which means that while they might have "known better" about the rectification, they didn't have a clue about the mechanism.

On educating the group's weaker links? It's still going on.

I'd prefer something that paid better - in money, or - failing that - gratitiude, but my persistent attempts to do better over the past five years haven't paid off.

-- Bill Sloman, Nijmegen

On a sunny day (Sun, 12 Apr 2009 02:31:50 -0700 (PDT)) it happened snipped-for-privacy@ieee.org wrote in :

Apart for 'why do you have to quote everything (I snipped it), and apart of you being wrong or partly right, or wrong about others, I will not go into that, just for fun, you are destined to fail (in your attempt to 'educate'. Think for a moment neural net. We all are -neural nets-. Rather complicated at that. So you think that by repeating your 'vison' of reality, other nets will, giving enough repeats, adjust their 'weights', so they will have the same world view as you (be it on global heating, politics, and / or detection of RF signals). However the NNets are a lot more complicated, first they are hardwired in early youth, so basic viewpoints and ways of reasoning will likely not change, second they protect themselves from dissenting views with for example kill files if it gets too much. So repeating what you have read in books in your early days will not change any adult opinion here,

-even if you were right-. The true 'understanding' (call it 'realization' happens only and ONLY when a neural net is already on the trip point, and the person him - her -it- self makes the connection in their own net. So you can mention an idea, but the chances of it having an effect are extremely small ... Like you stop smoking to end global heating, or do away with Edison bulbs to change the climate,. It is only because you were brainwashed in the school system, what for you seems to have been in universe-city, that you now think the school system is what makes people understand. It only makes some parrots. Understanding is an individual matter. So.. give it up, have some nice electroshocks, enjoy life while it lasts, and have fun.

beep

Who would come ?:-)

...Jim Thompson

On Apr 12, 2:31=A0am, snipped-for-privacy@ieee.org wrote: [....]

Here you made an error. It is not purely a matter of the transconductance of the input. A MOSFET op-amp input that followed the exact same transconductance rule as a bipolar circuit has less of a problem with EMI.

EMI causes a current to flow in the input terminals of the bipolar op- amp that would not be there in a MOSFET design. This added bias current develops voltage drops on the circuit resistors.

The problem can be very bad in the op-amps that have a bias current canceling circuit sort of like this:

--+---------+------+-- ! ! ! Q4 e\\! !/e Q3 ! PNP !--+--! PNP ! /! ! !\\ ! ! ! ! !/ ! ----+----! NPN Q2 ! !\\e ! ! ! !/ IN -+--------------! NPN Q1 !\\e !

The current mirror is not linear enough for the case where the NPN Q1 has a large AC current in it.

On others, the fact that the hfe of the transistor varies with the collector current is what is mostly to blame.

You have sure picked a bunch of "weaker links" to "educate" about the opamp RFI issue, people like me and Joerg. People who actually design electronics and deal with this issue in real life, in real time, using real parts and real numbers.

What an ass you are. Do you even own an oscilloscope?

And you still can't understand why! So much for genius.

John

of

That's a point of view. Trying to use it to predict the responses on this user group is a waste of time. Psychologists who try to use neural nets to explain much simpler phenomena don't do well.

-- Bill Sloman, Nijmegen

Nice theory, falsified by the fact that 26mV isn't enough to circulate any significant current through the components that you'd like to blame.

Try to think a little harder next time.

-- Bill Sloman, Nijmegen

But your theory is barely good enough to solve the problems that you have run into so far; not so bad that you had your nose rubbed in its defect yet, but still inadequate.

Not at the moment.

I understand why. And short of reforming Dutch attitudes to elderly workers, there's not a lot I can do about it. This isn't - of course - your theory on the subject, but you do have a well-established habit of having daft theories about stuff you don't know much about.

-- Bill Sloman, Nijmegen

If certain theories solve all the problems at hand, how can they be inadequate? A designer uses the theories that work, and not more complex theories, to paraphrase Einstein.

The first two terms in the power series are adequate, except when they aren't. Requirements, judgement, and experience decide how far you need to go. That's called "engineering."

I have about 50.

I have a well-established habit of designing things that work, for everything from NMR to FTIR to lasers to ICCD cameras to pipelines to jet engines, and selling them to people who care more about performance than price. I wouldn't trade that for your well-established habits. And I don't give a damn what anybody's attitude is toward elderly workers; they'd have to call in the National Guard to stop me.

Current project: a rackmount box with a mini-ITX SBC inside, connected via PCIe to our multifunction board containg DDS synths, fast ARBs, a

Get off your ass and do something.

John

Ah, you are expert on that also? I have some considerable experience with the 'human mind', for example