PCB Funny:

And the circuit board designer was very experienced. Notice how the resistor and capacitor reference designators are in order right to left, bottom to top. This is called back annotation. After a schematic is complete a board layout person (through CAD) places the parts layout on the board and connects the traces. So at that point R and C values from the schematic are placed Willy nilly (many boards fit that category). This makes troubleshooting a board a pain. You’re looking at the schematic and have to hunt all over the board to find R19.
I only had to design, layout and troubleshoot one circuit card to realize, this is dumb. So on the next design, after it was laid out, I had the board layout guy relabel, left to right, top to bottom, all of the components. These new reference designators were then back annotated into the schematic. So when it was released into to production, troubleshooting and field service folks were very appreciative of the time saving thought. This was back in 1978 when I did my first design.
 
Last edited:
Don O said:
And the circuit board designer was very experienced. Notice how the resistor and capacitor reference designators are in order right to left, bottom to top. This is called back annotation. After a schematic is complete a board layout person (through CAD) places the parts layout on the board and connects the traces. So at that point R and C values from the schematic are placed Willy nilly (many boards fit that category). This makes troubleshooting a board a pain. You’re looking at the schematic and have to hunt all over the board to find R19.
I only had to design, layout and troubleshoot one circuit card to realize, this is dumb. So on the next design, after it was laid out, I had the board layout guy relabel, left to right, top to bottom, all of the components. These new reference designators were then back annotated into the schematic. So when it was released into to production, troubleshooting and field service folks were very appreciative of the time saving thought. This was back in 1978 when I did my first design.
Click to expand...
is this English?
 
Robert Herndon said:
Found online. No other data available...

View attachment 72534
Click to expand...
I have often enjoyed the little messages written inside the amps.
But I didn't know who was writing them until now.
I always thought VHT was Chinese....I had no idea.
The last one I worked on was definitely Chinese.
Being the Teflon wire ceramic socket Curmudgeon that I am, I sort of had a laugh.
 
You must log in or register to reply here.
Back
Top