[sdiy] Integral scope on VCO

[KA4HJH]

>>  You really think so? Anything going on in the VCO is at ultra low
>> impedances compared to the CRT and the deflection amps. In any case
>> there's not much of a magnetic field to worry about (I'd worry more about
>> the fields from the HV power supply transformer affecting the CRT...)
>
>That's what I'd worry about... as well as magnetic fields interefeing with the
>scope.

Thomas, you're in good hands on this list. Take it from the "old"
timers--having a small scope in your modular synth is cool looking--and
even useful--which is why you probably shouldn't build it into another
module such as a VCO. Avoid the issues Harry and others have raised and
make it a module all by itself. That's why we call them MODULAR synths! If
you want to you can normalize the output of a VCO or a VCF to it behind the
panels.

This is IMHO more useful and will let you concentrate on getting the scope
working and eliminating any problems with RFI, EMI, etc. It will also move
the high voltages even further away the rest of your modules, reducing the
possibility of a catastrophic short.

Finally, if you get it all working and post the design then anyone can
incorporate it into their modular in any way they chose. I'm sure lots of
people would love to have one.

All this is purely my opinion but I think you'd be better off in the end.


BTW, I don't know if anyone else mentioned it but Eric Barbour used to have
a collection of old schematics that had a lot of useful info on building a
small scope just like this. He's not on the list right now but you can
email him at synth at metasonix.com. I have a copy myself but I'm not sure
where it is right now...

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"

"By the end of Chuck Statler's 'Rock Videos' of Devo we agreed that even if
Devo did not take the stage it was still the best concert any of us had
ever attended." --Kim Thayil (Soundgardern), 1995