Polisix, Scopes and more

Harry Bissell harrybissell at prodigy.net
Mon Oct 25 05:55:51 CEST 1999


IMHO: A scope should have two channels to be really useful esp. in
debugging oscillators... and "Triggered Sweep" is a must. This lets the
scope lock on waveforms as they rise or fall and gives a stable picture
on the screen.

Look for used scopes... try industries or colleges and tell them you are
a student learning electronics... sometimes you can get something for
$50 - 100 US.  If you have doubts as to the model...e mail us and we'll
give an educated opinion (but to keep us honest... don't tell us where
the deal is at..... hahaha)

:^) Harry

Roel Das wrote:

> Hello again.
>
> I've been building some circuits (a keyboard
> interface, VCO, VCA, ADSR and LFO), and i think it's
> time for some more questions...
> The ADSR and LFO don't seem to work the way they
> should, (not at all for the LFO), where do you start
> when debugging such a thing? I don't have a scope, so
> i'm limited to my ears, 2 multimeters (one really
> bad), and some cables...
>
> Next question; it would be usefull to get a scope
> anyways, but the moneys all gone... Velleman sells a
> digital scope for about 200 €(euro).  The numbers: 1
> channel, 5MHZ max sample freq, 1MHZ BW inputstage,
> timebase 20s to 2us in 22 steps, 5mV to 200V in 12
> steps.
> And then there's the computer-thing, a very nice
> digital thing that you connect to the computer.
> 3250€(euro), got about anything i think. Even a
> spectrumanalyser. And this one is 2 channels. I would
> love to get something cheaper though. Any thoughts on
> this?
>
> And then the POLISIX.
> One of my friends got a dying polisix. One of the
> filterchips is probably dead, i'll be testing it next
> weekend.
> But there's another problem. Sometimes when you put it
> on, the programmer-section acts weird. All the lights
> keep burning, and the synth seems to be in manual
> mode. The memory doesn't work then. If you put it on
> again, it might work just fine. You never know.
> And i think there's also a problem with the mod
> switch. The MG is always assigned to the VCO, no
> matter where you put the switch.
>
> I'm waiting for answers...
> Thanks in advance...
> Roel
>
>
>
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