[time-nuts] Rapco 1804m

[Paul Flinders]

Hi

Just joined the list - recently acquired a Rapco 1804m, mainly to use as 
a frequency standard, especially to have something to check the FE-5680A 
that I have.

The unit itself seems to work OK - connected to a cheapie puck style GPS 
antenna I got a 2D fix, occasionally 3D which corresponded pretty well 
with my actual location and "Coarse" oscillator lock, but never "Fine". 
It's the version with an OXCO rather than local Rubidium oscillator.

I've read David Taylor's notes and had a hunt through the list archives 
- I suspect I need a slightly better antenna, or a better position for 
the one I already have. It had a decent enough view southwards/southwest 
but somewhat obstructed to the north and north-east and comparing the 
visible satellites on my 'phone it was certainly the 
northerly/north-eastern ones that had low or no signal strength.

However I could really do with a copy of the manual, at least to 
understand the difference between "Coarse" and "Fine" locks on the 
oscillator - does anyone have an electronic copy that they would be 
willing to let me have? Or a physical copy - I'm happy to pay a 
reasonable sum.

Also is the serial protocol for these documented anywhere?