[time-nuts] LORAN C simulator operational

[paul swed]

A few weeks back I started a discussion on the demise of LORAN C. It was
quite a long discussion and spawned several others.
I will indeed miss LORAN C as a frequency reference for several reasons. It
was very good more stable then wwvb on the east coast.
And for 10 years I have had 3 austron 2100 and 2100f frequency monitors.
I used LORAN C to set my RB standards. Granted I also have GPS using the hp
3801.
So with the shutdown in Jan I hated junking the Austrons they are nice
comparators.
Recently, 2 days ago I set out to see if a LORAN C simulator could be
created that was simple, effective, and inexpensive. Using very common parts
and minimum of wiring.
It would appear that it can be done.

What I am using is 5 cmos chips CD 4000 series gates and counters and a
parallax SXb micro programmed in basic.
These have allowed me to emulate the master stations and the GRIs along with
the phase reversals needed to identify a master.
Using 2 RB standards a HP5065a as the master to the simulator and a cel
tower RB pull and both had been set to LORAN C and checked with GPS the
austrons tracking the simulated  LORAN signal in 1-7 E-12th range as
expected.

This is very fresh data as this has been running about 5 hours now and there
could be issues.
More time is needed to cleanup the software about 100 lines of easy code
thats simple and consistent in operation. (Read this as not tricky and
really boring)
Other comments the waveform is simple no attempt has been made to actually
create the wave shape. (Part of the KISS principle)
I really wanted to see what I could get away with. Still do wonder if I need
the phase reversals.

Now if there is interest I will need to figure out how to share the details
and code.
Will be on a business trip for the next few days so may not see a reply.
Regards
Paul