Hi Tobias, IT drop should have been IR drop. --mike
On Fri, Jan 31, 2020 at 7:14 AM Mike Ingle <finndmik...@gmail.com> wrote: > Hi Tobias, > > I agree with Tom, that I also like PTC fuses, but don't forget that they > have a sometimes significant IT drop. Been there, been burned. > > --mike > > > On Fri, Jan 31, 2020 at 3:36 AM tom burkart <t...@aussec.com> wrote: > >> Hi Tobias, >> additional answers below: >> >> Quoting Tobias Pluess <tobias.plu...@xwmail.ch>: >> >> > a) is it acceptable to route some signals under the GPS module? As >> > one can see, the signals I have routed under the GPS module go to >> > the front panel interface, i.e. they are not highspeed signals or >> > so, but I still wonder whether you experts would worry about it >> > (like "oh no, routing anything near the GPS module will disturb it >> > and decreases its sensitivity" or something). >> This violates constraints as set out in the Ublox hardware integration >> manual. >> >> > b) would you worry about the switching regulators? I know linear >> > would be better, but the professional GPSDOs also have switchers, >> > and besides that a linear regulator would not be so nice because my >> > power supply will be at least 15 volts. >> I would, but it can be dealt with. >> >> > c) is the usage of a RS232 chip a good idea or would you kick that >> > out because they produce such massive amounts of EMI that it will >> > disturb my GPS module or OCXO? >> Keeping it away from sensitive circuits will probably suffice. >> >> > d) is it a wise idea to use an LC filter for the OCXO power supply, >> > or does this lead to another rabbit hole because the inductors will >> > pick up magnetic fields (50 Hz...) and modulate the OCXO? >> All depends whether you will bath the whole thing in 50Hz stray >> magnetic fields. ;-) >> >> > e) anything else important I forgot? >> - Please double check your wiring of the GPS module it looks back to >> front. >> - In some places your ground layer is severely broken up to reduce its >> effectiveness. >> - Your antenna seems very close to the 1pps output and has traces >> underneath it >> - I quite like resettable PTC fuses (no need to replace) >> >> Tom >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.