Fluke.l is using my design except for a number of units which were shipped with 0 ohm resistors where the 3 diodes were supposed to go. This powers the CPU with 5 V instead of 3 and most don't last long at that voltage. However, the symptom is a blank display.
Also, I understand some units have an actual 5 V regulator and some expect a regulated 5 V. I have tested a total of 9 units, 2 from fluke.l one from Dan Karg and the other are mine against 3 Thunderbolts (2 group buys and one of the original red boxes) and they all work. As long as the serial data is enough to bias on and off the 2N2222, it should work. Check the wiring and check that the serial data goes to the CPU. There is not much that can go wrong if the CPU is working. It is possible that the serial input to the CPU is fried while the rest of the chip works, but I have never seen that happen. Yet I have fried a number of these chips (I design HV supplies in my day job). Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -----Original Message----- From: Chris Albertson <[email protected]> Sender: [email protected] Date: Wed, 13 Apr 2011 17:19:25 To: Discussion of precise time and frequency measurement<[email protected]> Reply-To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] Thunderbolt serial port problem UPDATE On Wed, Apr 13, 2011 at 5:11 PM, bill <[email protected]> wrote: > ... I bought from flukel (sp) in China. I opened up the monitor > and re-soldered > some questionable solder joints and it still doesn't work. The monitor > reports "Waiting for > GPS" and "No Message" fluke.l's design is not reliable. I don't think he is getting the voltages right in the serial interface. It works I guess but with small margin for error ===== Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
