This is indirectly related to ars, though I am reluctant to say exactly
how.  I need a contact with someone who could get me a few rare matched
electronic parts.  The most likely people to have these would be op amp
and related designers.  If any are lurking on this group, please send me
email.  We will most likely have to meet, so west coast/silicon valley
folks prefered.  Keith Henson

In article <6klfl1$...@basement.replay.com>,

The usual way to get matched components is to buy a lot of them and test
to your spec.  Or test a mess of them and pick two that match across the
profile.

If they're opposites (like matched PNP/NPN transistors for a push/pull
amp), it's trickier but pretty much the same game.

If you're trying to match thermal characteristics, it can get especially
tricky.

Depending on the components and the precision you require, you'll usually
either need specialized test equipment or excellent standard tools plus
lots of ingenuity to do a good job of component matching. People with
such skills don't come cheap, and precious few of them are stupid enough
to play your kind of games, Henson.

Chances are, you'll have to pay full price.  Which may not be an option, I
presume, since all your spare cash is going to payments on the 75 grand,
right?

Personally, I'd charge you triple, by the minute, and with an ironclad
requirement for matching funds to your richly-deserved copyright judgment.

- Whippersnapper

"...he reflects upon his many heinous crimes."  -- Calvin

 WHIPPERSNAPPER may or may not have said:

-> I could probably help you, Keith.  But it's not very likely I will!

I doubt that, somehow.

-> The usual way to get matched components is to buy a lot of them and test
-> to your spec.  Or test a mess of them and pick two that match across the
-> profile.

-> If they're opposites (like matched PNP/NPN transistors for a push/pull
-> amp), it's trickier but pretty much the same game.
->
-> If you're trying to match thermal characteristics, it can get especially
-> tricky.
->
-> Depending on the components and the precision you require, you'll usually
-> either need specialized test equipment or excellent standard tools plus
-> lots of ingenuity to do a good job of component matching. People with
-> such skills don't come cheap, and precious few of them are stupid enough
-> to play your kind of games, Henson.

Keith happens to be one of the people with such skills, whip. Try looking up
his patents sometime.  It's rather funny watching you try to be pedantic with
him.  

-> Chances are, you'll have to pay full price.  Which may not be an option, I
-> presume, since all your spare cash is going to payments on the 75 grand,
-> right?

Sure.  Right after your nut-cult pays Larry Wollersheim.

-> Personally, I'd charge you triple, by the minute, and with an ironclad
-> requirement for matching funds to your richly-deserved copyright judgment.

What skills could you possibly have that Keith would want to pay *you* for?

-jcr

: I could probably help you, Keith.  But it's not very likely I will!

I doubt you could whipper.

(snip teaching grandpa to suck eggss)

Whipper, look up my first patent, about a 4 quadrant log-anti-log
multiplier.  Think about what that took in matched parts.  Keith Henson

             Tommy

--

"The fact that Scientology or it's members may have done something
illegal
has no bearing on the Keith Henson case."

"I don't make the mistake of mixing my beliefs with reality.."

                Keith (Gunbunny) posted to a.r.s.

In article <hkhensonEu0Fzo....@netcom.com>,

"Variations of the transistor gains among the transistors connected in the
loop induces a linear error which may readily be corrected by adjusting
input resistances in the input signal paths. A compensation resistor is
connected between the base electrodes of the first and fourth transistors
of the loop; the compensation resistor is provided with a compensation
current derived from the collector electrode of the fourth transistor. The
compensation current is adjusted by setting the value of the compensation
resistor, which provides a correction for the error in the circuit created
by the ohmic resistances of the transistor emitters."

I suppose you didn't think I'd look it up.

- Whippersnapper

"You don't have to explain something you never said." -- Calvin

: Not having tried the device, I can't say, but it's clear you didn't match
: them perfectly:

: "Variations of the transistor gains among the transistors connected in the
: loop induces a linear error which may readily be corrected by adjusting
: input resistances in the input signal paths. A compensation resistor is
: connected between the base electrodes of the first and fourth transistors
: of the loop; the compensation resistor is provided with a compensation
: current derived from the collector electrode of the fourth transistor. The
: compensation current is adjusted by setting the value of the compensation
: resistor, which provides a correction for the error in the circuit created
: by the ohmic resistances of the transistor emitters."

: I suppose you didn't think I'd look it up.

You looked it up, but you don't seem to have understood what you read.
The first sentence is about correcting for effects which are on the same
order as the errors in the input (gain) resistors.  The second is about
correcting for errors induced by the ohmic (non log) resistances which are
a small source of error even for ideally matched parts.  (Then you have
third order errors due to drift with temperature.)

Keith Henson

In article <hkhensonEu9xzs....@netcom.com>,

You said:  "Think about what that took in matched parts."  I did.  It
obviates the need for matched parts!  You're a lot of smoke, Henson.  The
invention is clever (has it seen any actual use?).  Why you used it as an
example of omigod how awesome its requirements for matched components... I
can't imagine.

You were hunting a way to seem superior, I suppose.

You said:  "Think about what that took in matched parts."

The invention says it over and over.  It compensates for mismatched parts:

"It is yet another object of the present invention to provide an
electronic analog multiplier ... where in the mismatches between the
transistor junctions and the error induced by ohmic resistances of the
transistor emitters are readily compensated..."

"Gain error ... is readily compensated by simply adjusting input
resistances ..."

"The system ... readily generates a correction signal to be fed back into
the transistor loop to compensate for the ohmic resistances of the
transistor emitters."

"To calibrate and correct for errors from junction mismatches, an
appropriate input resistor R is adjusted..."

Et cetera.  All of which you know, or is your name on there by mistake?

What a maroon.

Like Archangel, your prejudice makes you stupid, and it makes you assume
I'll be stupid too.  (I have Deming on my bookshelf, three feet away.)

- Whippersnapper

"I control your fate! Your very LIVES are in my hands!"  -- Calvin