GPS receiver for LNAV

On Tue, 28 Apr 2009 18:45:48 -0700, rhpf wrote:

On Apr 28, 2:05Â*pm, soaringtheskies soaringtheskies.
wrote:
The LNAV, according to the manual, requires GPRMB and GPRMC sentences.
I'm wanting to use as much of it's functionality as possible. Â*I'm
using an EW MicroRecorder as a logger, unfortunately although this can
be used to supply a GPS signal to other things (it has it's own
receiver) it does not transmit GPRMB sentences. Â*So "all" I'm after is
a GPS that will transmit both GPRMB and GPRMC sentences to my LNAV, it
doesn't need to be able to log anything, although I see the point about
needing something to transmit the next waypoint to it. Â*Might end up
putting that LX back in...there must be soemthing simpler out there
though.

I'm also running SeeYou Mobile off a PDA, but I don't think there's any
easy way of getting this to talk to the LNAV.

--
soaringtheskies

Any older inexpensive Garmin with transmit the sentences you need and
allow you to transmit the next waypoint.

The OP wanted to avoid taking up panel space with the GPS, which rules
out putting a waypoint into it.

However, putting that type behind the panel merely provides another
gotcha with at least some of them: the ON switch.

If the GPS has a mechanical on switch, no problem. Just wire it to the
main battery and strap it down behind the panel, making sure the
batteries are out and the switch is ON. This way it will wake up when you
turn the master switch on.

However, many Garmins have a 'soft' power switch. I know the GPS II+ has
one and IIRC the 12XL has as well. The problem here is that after the
glider power is on you still have to prod the 'on' switch on the GPS,
which is hard to do if its OOS behind the panel.

====

Another problem with the older Garmins is that they will all stop working
in a few years. The 12 channel Garmin models (12XL, II+, III+ and others
of the same vintage) all contain battery-backed RAM which is kept alive
by a factory-fitted lithium cell. Will replacements for these cells still
be available when they start to die some time after 2011?

My first GPS II+, bought in 2001, was from a batch fitted with faulty
lithium cells. In mine it failed just after the GPS guarantee ran out. I
rang Garmin, expecting to pay for a new cell to be fitted but they told
me that that, although the GPS guarantee was quite short (1-2 years), the
Li cell had a 10 year guarantee and offered to replace it for free.
However, I noticed that in fact they replaced the entire GPS, so swapping
out the Li cell may be quite a difficult job.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |