[time-nuts] Re: Disabled Thunderbolt

[Francesco Messineo]

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 at 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
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