Rough Science and position finding

[Paul]

Time is always the critical thing when measuring longitude.
Rough science talks of time keeping using a pendulum to keep time, but the whole system falls down without a calibrated local or GMT noon signal.
Using a sextant, star fixes, and a good up to date almanac is an alternative. BUT even then the tabulated reading are roundups/downs of maths so all have errors. Besides, when learning to sail I tried a sextant. Nearest consistant accuracy I could get was 1/2 a degree or 2 minutes longitude time.

Having said that, total destruction of all comms gears seems a bit unikely.
After all what would be the use of prepping?????
I've made a trench radio before. Dead easy except for the blueing of the razor blade and getting my pencil sharp enough to get the detector to run sweetly (never could get a safety pin to work!). THat enabled me to listen to the 200khz Rugby Transmission and a host of MF stations.
I've got to believe some automated transmitter on LF or even MF will be running.
If nothing is, why would you need to locate yourself anyway.
My goal was to learn the ability to aid a search party to my location. If there is no technology ANYWHERE, what's the point is calling for help???