Navtel 9460 Protocol Analyzer info?

Tony Duell ard at
Wed Apr 13 18:49:06 CDT 2005

>  IIRC one of those 'polar relays' is not- it's actually the QBF 
> message generating coder-a very clever little electromechanical device 
> with a "disc" memory.  And that spiral timebase was something else - 

Correct. The 'disk' is a circular PCB that has the QBF message stored in 
the trace pattern. It's read out by a set of brush contacts that touch 
the pads on the PCB as the latter rotates.

The manual I have for my TDMS (and which I can't instantly put my hand 
on...) has a section in the back covering dismantling, assembling, and 
aligning this 'coder'.

Although it's the same can and plug base as the polar relay alongside it, 
the locating pins are swapped round (one being larger in diameter than 
the other) so you can't get the the wrong device in the socket.


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