Re: [ARSCLIST] square waves....Re: [ARSCLIST] Libraries disposing of records

["Steven C. Barr(x)" <stevenc@xxxxxxxxxxxxxx>]

----- Original Message ----- 
From: "phillip holmes" <insuranceman@xxxxxxxxxx>
> A square wave on a record doesn't look like a square because of the 
> velocity involved--or something--that I can't explain.  A square wave is 
> built up of stacked "odd integer harmonics" and contains multiple 
> harmonics.  Somewhere around 12 harmonics, it really looks like a square 
> wave.  The more harmonics present, the more perfectly formed the square 
> wave becomes.  A perfect square wave would require infinite bandwidth 
> and infinitely fast electronics (forget the stylus, we can't even 
> generate a perfect square wave, only a mathematical representation of 
> one). 
>
Now...let's assume we have a DC battery and a switch...so the output
of the combination is either "current" (switch closed, DC voltage
present) or "no current" (switch open, no DC voltage). We physically
flip the switch between the two, say, five times per second. Since
the voltage rises from zero to X as soon as the switch makes contact,
don't we get a five Hertz "square wave?" Assume we have nice straight
wiring (no inductance)...what, if anything, would distort the wave
shape of our output?

Steven C. Barr