[aprssig] GPS 15H-W OEM Module
lmcdavid at lmceng.com
Thu Sep 16 21:45:37 CDT 2004
Regarding the recent reflector questions about Garmin OEM GPS receivers:
I am using a Garmin 15H-W OEM GPS receiver in a mobile installation.
This receiver has a MCX board-mounted connector for a remote GPS
antenna; there is no on-board antenna.
The receiver is a single board, 1.8 x 1.4 x 0.33 inches with
soldered-in-place shield cans over the entire board surfaces (both
sides). The MCX receptacle connector protrudes slightly from one corner
edge. There is a tiny, 8-circuit power/data connector along one edge also.
The 15H-W comes with a mating power/data connector, which is provided
with eight individual, unjacketed wires about 8 inches long. You will
need this cable assembly!
I had a lengthy discussion by email with a Garmin applications engineer
about powering the remote GPS antenna. The 15H-W includes an excellent
switching power supply allowing a wide range of input voltages; this
supplies 3.3 vdc to the receiver and 3.3 vdc to the remote antenna.
So, what if your remote antenna expects 5 vdc? Well, there is a
diode-protected input on the power/data cable for external antenna
power. So, you just provide separate, regulated 5 vdc to one of those 8
wires and this is directed to the MCX antenna connector; the internal
diode isolates the receiver's 3.3 vdc power to the antenna.
Very early versions of this receiver required cutting a trace to remove
the internal 3.3 vdc to the MCX connector; but, all current production
(and for at least a year now) has included the isolation diode.
I had The RF Connection build for me a 6-inch long male, right-angle MCX
to female bulkhead BNC cable assembly. I then mounted the 15H-W in a
diecast zinc box with some power control circuitry.
I mounted a through-the-roof Larsen NMO active GPS antenna permanently
on my station wagon roof. Very clean...
Keith - VE7GDH wrote:
> The Garmin GPS 15H / 15L does NOT have an antenna built in...
Larry McDavid W6FUB
Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland)
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