[time-nuts] tube GPS receivers

[Jim Lux]

I think that doing the PN code and correlator is something that could be 
done with tubes (especially if you didn't want to go P-code).

I suppose you could use a counter to record the changes in code phase as 
you scan for the correlation peak, so that gets you your numeric code phase.

Getting doppler as a number for computation might be tricky, but you 
could probably solve for the position and clock offset without using 
doppler.

Decoding the nav message at 50bps should be straight forward.


Hmm. what about implementing the nav calculation as an analog computer. 
ANalog multipliers were built using vacuum tubes.