0

VCO no output
Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.

VCO no output

by puddyman on Sun Sep 17, 2017 9:28 am

I've had this kit for over 6 years now and still not finished it!

I'm up to the part where you build the VCO, put the scope onto R105 and a convenient ground. All i see is a flat line on the oscilloscope :(
I don't hear anything if i try putting headphones between ground and R62.

I've verified 3v between R81 and R90 when my power supply and variable voltage cicuit (from 9v battery) is connected
I've verified 3v between R81 and pin 7 on the chip
i've verified power coming from power supply at J4 is 11.83v and 5.33v

multimeter between R81 and R105 is 0v

can anyone help me out?
puddyman
 
Posts: 19
Joined: Thu Sep 23, 2010 3:55 pm

Re: VCO no output

by puddyman on Sun Sep 17, 2017 9:55 am

seconds after posting this i realised i've been probing the top of the resistor and not the bottom!
it works!
puddyman
 
Posts: 19
Joined: Thu Sep 23, 2010 3:55 pm

Please be positive and constructive with your questions and comments.