Wayne Wrote: > I measured the output voltage at the output BNC at 2.5V. A pigtail > seems like a reasonable approach to me. > > > Wayne
OK, that sounds like a 5V square wave to me. So you will need two resistors, a 50 ohm and 25 ohm is perfect, but if you can't get those a 47 and 27 will also work fine. For the pigtail you want a fairly thin flexible cable with a stranded center wire. A big stiff coax like RG59 could easily rip the pad off the board, I doubt Sean is going to warantee that! First you need to find the right pad to use, I don't have it in front of me, follow the traces to the 74HCU04 chip, one pad goes to an input the other to an output, you want the pad that goes to the input. Connect the 50 ohm resistor to the pad and the other side to a handy ground point, if there is a ground trace or via to the ground plane that would be best, but if not, if I remember correctly, the neg lead of the big cap is right there. The shield of the coax goes to the ground point and the center conductor goes to the 25 ohm resistor whose other lead goes to the pad. The two resistors are in series between the center conductor and ground with the connection between them at the pad. Thats it. Just remember to keep the resistor leads as short as you possibly can. You want to use small low inductance resistors. Its also a good idea to mechanically attach the cable to the board somehow such as a dab of holt melt glue. Thats really it. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=24800 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
