Hello All, I had a thunderstorm with a close discharge, the flash and bang were simultaneous. And very loud/bright. I found no sign of a ground strike, but I had damage from the EMP. My Broadband modem was damaged, the router died (all the lights went out and the power supply ran hot). All the ethernet ports were blown out. When I looked at my Thunderbolt disciplined clock it was still running. Lady Heather showed no signals from the thunderbolt. After faultfinding everything, a serial port on the computer was dead, the thunderbolt output was silent, but it was still outputting PPS and 10MHz. The antenna on a mast 4 feet above the roof was OK. The serial port on the old PC was a plug-in card, but the other ports on other cards still work. Eventually, I set up another GPS receiver and compared the PPS signals. The thunderbolt still works but has been struck dumb. After power up, the tbolt synchronises with the satellites and sends PPS and 10Mhz. What I want to know as it is not clear in the Thunderbolt manual, just what systems run when you do not send any commands to the tbolt on start up? Does it do a survey, or is mine using a stored position, or does it do a new survey? Can I keep using the tbolt in spite of the fact that I can not not use Lady Heather again? cheers, Neville Michie

Not of much help, but: The tbolt doesn't do a new survey if the stored position matches (to a few meters afair). In a similar occurrence, many years ago, I've repaired a modem that was hit by a close EMP by replacing the RS-232 level translator ICs (75188, 75189 or whatever is used on a tbolt). HTH Frank On Sat, Apr 9, 2022 at 7:25 AM Neville Michie <namichie@gmail.com> wrote: > > Hello All, > I had a thunderstorm with a close discharge, the flash and bang were simultaneous. > And very loud/bright. I found no sign of a ground strike, but I had damage from the EMP. > My Broadband modem was damaged, the router died (all the lights went out and the power supply > ran hot). All the ethernet ports were blown out. > When I looked at my Thunderbolt disciplined clock it was still running. Lady Heather showed no > signals from the thunderbolt. > After faultfinding everything, a serial port on the computer was dead, the thunderbolt output > was silent, but it was still outputting PPS and 10MHz. The antenna on a mast 4 feet above the roof was OK. > The serial port on the old PC was a plug-in card, but the other ports on other cards still work. > Eventually, I set up another GPS receiver and compared the PPS signals. The thunderbolt still works > but has been struck dumb. > After power up, the tbolt synchronises with the satellites and sends PPS and 10Mhz. > What I want to know as it is not clear in the Thunderbolt manual, just what systems run > when you do not send any commands to the tbolt on start up? Does it do a survey, or is mine > using a stored position, or does it do a new survey? Can I keep using the tbolt in spite of the fact > that I can not not use Lady Heather again? > cheers, > Neville Michie > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there.