[amsat-bb] Re: G5500 / SatPC32 / Rotor control

[Alan P. Biddle]

Steve,

I have used a Labjack U12 with a NLSA Piggyback board, which can be seen
here:  http://www.nlsa.com/labjack/labjack_piggyback.html  It was an
absolutely plug and play system, powered by the USB port, which would give
you 12 bit ADCs.  It is supported by NOVA and SATPC32, among other tracking
programs.  Serial and parallel ports are slowly going away.  My new desktop
computer has neither, though I have installed some PCI cards to give me back
some functionality.  Of course there are USB converters, but I liked
something which eliminates the possible need for yet another lump of
electronics.  ;)  

Unfortunately, it looked as if the Labjack people had discontinued the U12,
and as you will see above, NLSA is no longer carrying the Piggyback board.
It was one of the great bargains, BTW.  Labjack has done another U12
production run, and apparently plans to keep it available as long as there
is sufficient demand.  Anyway, it is not hard to home brew an interface
between the U12 and the antenna controller, even using discrete transistors.
However, on the SATPC32 web site, is an originally developed schematic,
using a very standard buffer chip.  No PC board, but you could easily
duplicate it on a bit of perf board.  The driver chip and the 8 pin DIN jack
are not Radio Shack parts, but you can get them at most parts sources.
Exclusive of shipping, about $10 for everything except the DIN cable.  Of
course you will need to get the U12, but this is still a very reasonable
cost given the performance.  So if you are willing to do a bit of very easy
construction, the combination is definitely worth a look.

Alan
WA4SCA