Re: squeezing a field

On Fri, 25 Oct 2024 09:37:19 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

john larkin <jl@glen--canyon.com> wrote:
>

On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
 

john larkin <jl@glen--canyon.com> wrote:
>

On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>
wrote:

[...]

plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?

>
>

 
It is for people who don't actually work with real parts.

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>
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use
analogue computing to work out his designs  i.e. He built prototypes and
measured them.

 
You youngsters probably don't remember a time when there wasn't Spice.

>
Hey!!!   Who are you calling a youngster?!!!      :-)
>

I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.

>
I have a spreadsheet I wrote for calculating the relationships between
resistance, capacitance, frequency and time constant (put in two and the
others appear, put in three and the error% appears).   It also gives dB
loss below or above the 'cutoff' frequency.  Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
>
Those and a pocket calculator are still the only 'computing' I use for
design work.

For 5%, I'd just use the ratio of difference and starting value to
 multiply the parallel mate.

My own manually tabulated book of tables for parallel values assumed
an E48 or E96 (2 or 1%) rack of possibilities. Otherwise, why bother?

Took a while to complete, and only aimed at E24-type variations.
Still around here somewhere, though the dime-store binding is fubar.

RL
parts