Hi Bob As far as I'm aware there is no schematic available for the Thunderbolt, I'm pretty sure it would have been shouted here with glee is anyone had found one:-) If your specific requirement though is to monitor for failure of the 10MHz output then monitoring the DC conditions before any output capacitor doesn't strike me as being adequate. Whilst it's quite possible that a DC failure in the output circuit, or perhaps a significant change in DC operating conditions, could indicate a loss of the 10MHz signal, the reverse would not seem to be necessarilly implied, oscillator failure, for example, or other component failure earlier in the signal path, might leave any output section fully functional with DC conditions unchanged but still with no output. Are you sure there's no 1 PPS signal available? Observing short pulses at relatively long PRFs is notoriously difficult and has been commented on here on many occasions. A modern digital scope generally has no problem but triggering an analogue scope requires a bit more practice. Again though, even if you confirm that the 1 PPS signal is available and healthy that in itself doesn't guarantee that the 10MHz output is the same. It really comes down to just how important this is to you, if you really want to be sure whether or not there's a 10MHz output then that's what you need to monitor. It shouldn't be at all difficult, just a highish impedance pick off from the circuit board should do it, or a coax coupler on the output to pick off a small sample of the signal, plus a detector of some kind, perhaps even a 10MHz filter if you wanted a degree of confirmation that the frequency hasn't jumped significantly, you could probably do it all with off the shelf parts from Minicircuits without even opening the box, perhaps even on the cheap via Ebay:-) Regards Nigel GM8PZR In a message dated 23/10/2013 07:12:50 GMT Daylight Time, [email protected] writes:
Anyone have a link or PDF of the T-Bolt schematic? We are "never satisfied" with how things that seem to be working fine might fail one day in our critical environment SO: The object of the game is so if the T-Bolt fails to provide the 10 MHz signal that the loss of it will trigger a fail-over mechanism to a backup source so we built up a monitor-keys-a-controller circuit that watches the 10 MHz and while we DO have the Trimble PDF manual it doesn't have a schematic AND: Issue 1 is: We are monitoring the 10 MHz output of the T-Bolt and it appears to be AC coupled so this isn't as easily detected and we want to tap-in before the coupling capacitor to get a straight DC coupled signal for our special signal monitor circuit; that is one reason for schematic need PLUS: Issue 2 is: We see NO signal coming from the 1 PPS BNC jack and we hear that this is a port that can be enabled/ disabled and we are hoping one of you know how to enable it to output the 1 PPS which we might use to drive the monitor circuit OR: Optionally: how we might rewire it so we can get 10 MHz out of that "unused" jack to feed our monitor circuit. Thanks! Robert L. "Bob" Burchett WB6SLC Certified Communications Engineer Enterprise Electronics 22826 Mariposa Ave. Torrance CA 90502 Direct line: 310.534.4456 FAX: 310.534.1233 Website: www.EEonTheWeb.com _______________________________________________ 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.
