[Lowfer] Motorola OnCore GPS GT+ boards cheap.

[David Willmore]

I don't know why I didn't think to post this here, too. It
wasn't until N2APB pointed out that these could be used for
Coherent that it clicked.  Sorry for the delay, there should
be plenty left.

Basically, this is a board level (subassembly) GPS that needs
antenna, power, and comms from the outside world.  Give it
power and an antenna input, and it gives you serial data
containing fixes out.  It's a somewhat older 8 channel receiver,
but it's a pretty heavy duty product, so that makes up for it
a bit. :)

The antenna is supposed to be amplified, but I hacked up a version
of the one in the current QST article and it worked fine.  I've
been meaning to build an amp, but I've been having trouble finding
a design that uses parts that aren't discontinued--someone just
sent me some links that I need to check out.  I'm sure I'll find
on in there.

The serial output is 0/5V, so you'll need to hack together a little
MAX232 kind of circuit or just talk to it with a micro that wants
0/5V levels, anyway.  There is an example circuit on BGMicro's
web site (the guys selling these) and there is plenty of stuff
on TAPRs site--who's used similar boards in a number of projects.

Hmmm oh, yeah, the price. :)  They're selling them for $14.95
and they have a $6 S/H fee (for any size order, I think).  I've
been buying from them for years and they're great to deal with.
You can pick up all the parts you need from them to make the
interface, too--MAX232, 5V regulator, caps, 2x5 .1" centers header,
etc.

I've already got one in and have interfaced to it and it worked
just fine.  So, I organized a group buy with my local club.
Then it struck me that it might be useful as a station time
reference when you want to coordinate TX/RX with other stations.
Meterior scatter/EME both use schemes like that.  Schemes like
Coherent allow you to use a coherent (du-ah) receiver on a
signal by 'transmiting' the timing out of band (shared clock).
So, that's normally good for 3db or so.  Hey, free signal!

So, look up www.bgmicro.com part number ACS1397.  Download
their catalog and look through it.  They have torrids, FETS,
etc.  Plenty of VLF stuff in there.  No Litz wire, though. :(
I still can't find a source of that.

Okay, enough rambling.  Off to bed.

Cheers,
David N0YMV