DC bias problem

Discuss x0x construction and related issues

Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.
Locked
User avatar
xtals
 
Posts: 10
Joined: Tue Aug 08, 2017 1:46 pm

DC bias problem

Post by xtals »

Hi! :)

I've started to build my xox (from Zwillyx shop).
Following the manual at page 37 i'm supposed to test DC bias and have 8.5VDC, but when i put the multimeter probes i read a 0v value.
All other voltages are fine according the manual.

What you suggest to check?

Thanks!

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: DC bias problem

Post by antto »

you've probably received some printed build manual, but in the past most folks have used the online build manual, which is not paged like a book
so can you clarify exactly at what point of the build process you are that instructs you to measure that voltage?

User avatar
xtals
 
Posts: 10
Joined: Tue Aug 08, 2017 1:46 pm

Re: DC bias problem

Post by xtals »

Hi!

I'm using this manual:

http://www.ladyada.net/make/x0xb0x/fab/vco.html

I think that's the same from the Willzyx site after all!

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: DC bias problem

Post by antto »

most probably it's the same manual, printed on paper
but my question was: what is on page 37?

User avatar
xtals
 
Posts: 10
Joined: Tue Aug 08, 2017 1:46 pm

Re: DC bias problem

Post by xtals »

This:

Image

And that's the description:

"If you don't have a scope, you should at least measure the DC bias, which is about 8.5VDC"

Then, measuring with multimeter at the resistor i have 0V!

thanks

User avatar
xtals
 
Posts: 10
Joined: Tue Aug 08, 2017 1:46 pm

Re: DC bias problem

Post by xtals »

Update:

I have solved the problem: Q26 (2SC1583) had some really bad soldering on it...on the smd part a lot of solder paste was left unsoldered and then some pins was shorted.
Cleaned it with ultrasonic bath first and then resoldered, DC bias is perfect now!

Thanks again!

Locked
Please be positive and constructive with your questions and comments.

Return to “Making x0x”