amplify 40kHz audio signal using TL082: first two stages are fine, but high noise from the third stage

The DERF tranform, applied here, is described earlier in this thread.

"Fred Bloggs" wrote in message news: snipped-for-privacy@nospam.com...

Asked and answered. You may like repeating yourself, but I find it too boring for words.

This has been converted, via a process I will call the DERF transform [1]. This elision process conforms to accepted Usenet quoting practise with the exception that elided text is replaced by "[DERF]" and, where needed for grammaticality, short sequences with a '[]' pair are inserted.

"Fred Bloggs" wrote in message news: snipped-for-privacy@nospam.com...

Amazingly, all 4 of the DERF criteria applied to that elision.

Fred, can you find anything worthwhile to post about? With your probing and powerful intellect, surely you can do better than we've been seeing lately.

The DERF transform, applied here, is described earlier in this thread.

"Fred Bloggs" wrote >

Nor did you answer, except with garbage.

If you were as skilled at argument as you are at unsubstatiated and baseless assertion, you would be a force to be reckoned with.

Ok by me. Was there anything in particular, in the way of technical ideas or facts, that you found yourself unable to digest? (I imagine so! )

"Joerg" wrote in message news:KB6_d.11260$ snipped-for-privacy@newssvr14.news.prodigy.com...

Hi, Joerg.

very expensive, meaning they are out of budget for

I think the cost of those parts will come down as newer (and faster) fab lines come online and the ones currently dedicated to higher margin parts become available for "cheap" stuff.

some really old regular ones can still run circles

several milliamps in under a nanosecond.

For RF, the pad and trace capacitance can usually be dealt with by incorporating it into the transmission lines used as a matter of course. In that environment, power is mainly a function of signal level. The power I alluded to above is the power necessary to make circuits work when the capacitance must be driven at a higher impedance, typically much higher.

lot in the old days. That was because volumes of it

my utmost to avoid a single sourced part. This is

Heck, I even flung a SMPS design to semi-discrete once

Designing for volume over years is a special challenge, one which often precludes using the niftiest new parts.

discrete. The two that weren't used the AD603 which is a

I put a discrete amplifier in front of a predecessor to the AD603. It added cost, but got the noise down enough that management agreed with its use in a moderately high volume circuit. Later, I found out that a system level foulup had discarded about

Likewise, and thanks.

The DERF transform, applied here, is described earlier in this thread.

"Fred Bloggs" wrote in message news: snipped-for-privacy@nospam.com... [DERF]

Yes. I can be brought to tears by your antics and posturing.

I am quite willing for you to believe that. Fortunately for people who have paid me good money to design them, my detection circuits do the job required of them and have been copied into new designs done by others.

The OP has not yet indicated any desire for a replacement detector or review of his current detector. I have absolutely no desire to engage in any more [1] effort along that path. If my motivation was to prove something to you, I might be inclined to get one or more of my detectors drawn up in a suitable form for publication here. But, as you seem completely unable to comphrehend, I am not the least bit concerned about your low opinion. In fact, I treasure it.

For now, I decline for reasons stated.

Pure speculation, and false to boot. Delusional.

Fred, you completely misunderstand what I try to accomplish here. And I do not think you can, even when explained. But I will plant this little seed of doubt in your overwhelming superiority complex.

I consider my job well done when a poster goes away with his self esteem intact, more understanding than he/she had before, and her/his presenting issue solved to his/her own satisfaction. Whether this leaves you with a better or worse opinion of me and my skills is entirely immaterial to me. If anybody else reading is naive enough to think less of me because of my effort or yours, I consider that their problem, not mine.

You seem to think there is some kind of contest here. What you seem unable to grasp is that I am completely uninterested in the game(s) you like to play here.

I read in sci.electronics.design that Fred Bartoli wrote (in ) about 'amplify 40kHz audio signal using TL082: first two stages are fine, but high noise from the third stage', on Sat,

The appended 'isn't it' is characteristic of French ('n'est-ce pas?') and Welsh English (not Welsh Welsh) spoken language. Note that the 'it' in 'isn't it' has no referent in the preceding sentence, as in 'He's a really tall man, isn't it?'

I have different objectives in discussion with people who want to play games rather than get a technical problem solved. The clauses you cut off my sentence would make that somewhat more evident.

Nevertheless, if you are relating personal experience, I hope you feel better as time goes on.

"John Woodgate" a écrit dans le message de news:l93$ snipped-for-privacy@jmwa.demon.co.uk...

???

Sorry John, but I miss the point. Probably some more shade in my knowledge of english.

In passing, I note yet another unsubstaniated slander. People must be really dumb who believe such tripe.

How about making a real case? If that benign, two paragraph request for clarification is your best evidence of "beating up on newbies", I am looking forward to your presentation. Also, your perception of "ass handed" is comical and your conversion of my electing to not supplement the numerous other suggestions into a "retreat" is a good indicator of what games you prefer.

Make your case, without innuendo if you can.

Be careful who your heros are, John.

"John Fields" wrote in message news: snipped-for-privacy@4ax.com...

It's a state of mind which I reported and you already detected. What is there to prove? If you doubt it, then what was your point?

And look who's talking... Mr. Never-met-a-flame-war-he-didn't-like ;-)

...Jim Thompson

--- Yet you often leave behind little pejorative comments when someone disagrees with you which, if they're not responded to, can erode an unwary recipient's self esteem.

-- John Fields

It doesn't need to be truely wide band:

(1) A burst of the 40KHz signal reflects off the far object and is received. In the reciever, both the amplitude profile and the phase of individual cycles can be used in the calculation.

So long as the amplitude profile is short enough in time that the timing can be determined to within on cycle, the phase of the signal can be used to fill in the digits below that. If the filter is reasonably stable, a constant can be subtracted from the result to correct of its delay.

(2) The 40KHz can be frequency modulated. The narrowness of the filter makes the time between zero crossings change more slowly than in the transmitted signal. A micro can look at the series of values of the period of the signal. It can fit the numbers to a curve and determine when the curve passed through a certain value. This will give a value that again is only lated by a constant.

Larry Brasfield wrote: [...snip drowning rodent drool...]

Where's your workup on the 40kHz amplifier thread, fairy loudmouth boy? Can't go any further with 4KTRB and some other simple-minded trash? We are not surprised, windbag. You are one little superficial and worthless moron.

Larry Brasfield wrote: [...snip a bunch of hot air from pretentious little pussy...]

Where's your workup on the 40kHz amplifier thread, fairy loudmouth boy? Can't go any further with 4KTRB and some other simple-minded trash? We are not surprised, windbag. You are one little superficial and worthless moron.

Larry Brasfield wrote: [...yawn...] Where's your workup on the 40kHz amplifier thread, fairy loudmouth boy? Can't go any further with 4KTRB and some other simple-minded trash? We are not surprised, windbag. You are one little superficial and worthless moron.