[sdiy] Trouble shooting the PV-1 pitch to voltage converter

[Joe Frey]

Simon, And hopefully list.
> About the same voltage as on U04 pin 1 (i.e. dependent on the 
> frequency) should be present on U04 pin 7, is it?
Similar voltage is not on u04 pin 1 and pin 7.  I am sure that u04 pin 1 
is changing with the frequency though.

I am now starting again at the beginning. I am now at u02 which creates 
the pulses that drive the circuit. I am able to follow the schematic OK 
until I get to the input at u02 pin 11 and 12. This is 12.4 v which 
seems ok though it seems very similar to the positive voltage at the 
rails. I checked for a short but there wasn't one. I wonder, though u02 
pin11 is supposed to output a positive pulse to drive the counter but 
the voltage at that pin is only .001 volts?

> With a positive voltage at U04 pin 7 it is strange that you get a 
> positive voltage at the output, since the current going via R17 into 
> pin 2 of U06 would cause U06 pin 1 to go negative (there should be no 
> current going into Q04 (left) collector since with 0V at both the base 
> and the emitter it should be completely turned off) 

U04 pin 07 is 4v and on the other side of r17. U06 pin2 is 0v U06 pin1 
is -1v The Pitch CV out is -1v
Q04 pin1- 0v
             2  -.08
             3 -.5v
             4- -.5v
             5- 0v
             6- 0v
I feel like the part of the circuit that drives c05 works but that 
somehow it's never pushe to the 4th step of moving the c05 voltage to 
c06? It seems like u04 pin7 should fluctuate like u04 pin1. Thanks 
again. Joe.









Simon Brouwer wrote:
> Hi Joe,
> About the same voltage as on U04 pin 1 (i.e. dependent on the 
> frequency) should be present on U04 pin 7, is it?
> With a positive voltage at U04 pin 7 it is strange that you get a 
> positive voltage at the output, since the current going via R17 into 
> pin 2 of U06 would cause U06 pin 1 to go negative (there should be no 
> current going into Q04 (left) collector since with 0V at both the base 
> and the emitter it should be completely turned off)
> If the output were stuck to a negative voltage I would suggest 
> adjusting P02. I expect a normal voltage of around 0V at the base of 
> Q04 (right), and around -0.5V at the emitters.
> But if the output is stuck to a positve voltage something else is 
> wrong that has to be resolved first.
> Best regards
> Simon
>
> > Op 28 juli 2014 om 4:50 schreef Joe Frey <joe.frey at radioles.com>:
> >
> >
> > Simon, Thanks! Well, at very least you helped me feel like I might get
> > this going with help from bigger brains than mine.
> > As cheater00 pointed out, I didn't state how it wasn't working. I
> > only get a steady 5.3V at pad 4(Pitch CV). It does not change.
> >
> > > apply +12 V to PAD7, I wonder if the voltage on U04 pin 1 goes to
> > > around 0V (I think it should). If it does, leave PAD7 open again for
> > > the next check,
> > I did this and pin 1 of U04 went to 0V!
> >
> > > - if you apply a continuous input signal, do you see the DC voltage
> > > (as measured with a multimeter) of U04 pin 1 go down from the 11.4V
> > > that it is without input signal? Does it come closer to 0V at higher
> > > frequencies of the input signal?
> > Yes. U04 pin 1 I get .004-7.0 volts with the smaller values at higher
> > frequencies.
> >
> > Thanks. Again. Can you tell me where to look next? Joe.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Simon Brouwer wrote:
> > > Hi All,
> > >
> > > Apparently the gate signal is stuck to "on". I don't understand how
> > > this part of the circuit is supposed to work, how can the gate signal
> > > ever go off if there is no input signal? Since in that case U07B is
> > > not getting clocked and will not change its output state...
> > >
> > > And Joe,
> > >
> > > For some first checks,
> > >
> > > - apply +12 V to PAD7, I wonder if the voltage on U04 pin 1 goes to
> > > around 0V (I think it should). If it does, leave PAD7 open again for
> > > the next check,
> > >
> > > - if you apply a continuous input signal, do you see the DC voltage
> > > (as measured with a multimeter) of U04 pin 1 go down from the 11.4V
> > > that it is without input signal? Does it come closer to 0V at higher
> > > frequencies of the input signal?
> > >
> > > Best regards
> > > Simon
> > >
> > >
> > >
> > >
> > > Joe Frey schreef op 27-7-2014 19:00:
> > >> The PV-1 is a pitch to voltage converter designed by Harry Bissel 
> and I
> > >> know of one person that uses it.
> > >> Needless to say mine doesn't work and I'm stuck. I have added a 
> link for
> > >> the original project pdf that has the schematic. There is a link 
> to a
> > >> pdf of my project with voltages listed for ICs, transistors and 
> diodes.
> > >> There are links to a photo of the top and bottom of the board I 
> made and
> > >> populated, Any help would be much appreciated.
> > >>
> > >> http://www.radioles.com/works/pv1_611-1.pdf
> > >>
> > >> http://www.radioles.com/works/PV-1%20trouble%20shooting.pdf
> > >>
> > >> http://www.radioles.com/works/IMG_20140724_230152028.jpg
> > >>
> > >> http://www.radioles.com/works/IMG_20140724_230201823.jpg
> > >>
> > >
> > >
> >
> >
> > --
> > ("> <")
> > / ) ( \
> > ''/ | / |``
> >
> > "Anything worth doing, is worth doing badly, because it might make 
> it better the next time." --anon
> >
> > Joe Frey
> > A.K.A. Bitter Relic of a Bygone Era
> > joe.frey at radioles.com
> > http://radioles.com
> > Chez Judex
> > http://radioles.com/judex/
> > Radio Lu-Lu (Internet radio)
> > http://radioles.com/radiolulu/
> >
> >
> > _______________________________________________
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> > Synth-diy at dropmix.xs4all.nl
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-- 
    (">  <")
    / )   ( \
  ''/ |   / |``
  
"Anything worth doing, is worth doing badly, because it might make it better the next time." --anon

Joe Frey
A.K.A. Bitter Relic of a Bygone Era
joe.frey at radioles.com
http://radioles.com
Chez Judex
http://radioles.com/judex/
Radio Lu-Lu (Internet radio)
http://radioles.com/radiolulu/