Update on CAI flight recorder repairs from CNi (GPS Date problems)

On Fri, 12 Dec 2014 09:19:24 +0000, Ian Reekie wrote:

At 19:48 11 December 2014, Tango Eight wrote:
We've had to change tactics slightly to deal with the Cambridge flight
reco=
rder GPS date problems recently discussed here on r.a.s.

Here's the latest:

Cambridge 302 needs a new GPS card to fix this the right way. Simply
solde=
ring in a new battery won't get your 302 through Winter storage (which
is w=
here *my* 302 vario is right now). Few people will want to remove a
vario
=
for the Winter to maintain the GPS date.

This problem will be repaired under our existing CAI 302 flat rate
policy:
=
we fix (almost) any 302 and provide a 1 year warranty and fresh
barograph c=
alibration for $350.

Cambridge model 10/20/25 flight recorders were always intended to be
mounte=
d in an easily removable fashion, so we feel that the battery only fix
is b=
etter economy for these older units. CNi will replace the GPS date
battery=
, fix your date problem and calibrate the barograph for $125. It will
be u=
p to you to maintain the battery by powering up the flight logger for a
few=
hours every 3 months or you will lose the date... there will be a
warning/=
reminder label on your returned unit to this effect.

Gary Kammerer handles all of our CAI service, please find contact info
for
=
Gary on our website.

Best regards and Good Soaring in 2015,

Evan Ludeman for ClearNav Instruments www.ClearNav.net please join our
forum for discussion of all things ClearNav
http://clearnav.net/simplemachinesforum/index.php


With regards to the older Cambridge loggers ie model 25.
Is it feasible to mod the logger such that the GPS internal real time
clock is powered off the same user replaceable 3v higher capacity
lithium battery that provides the loggers seal ?
I was stupidly thinking of a wire and a low V drop diode ? (Would this
mod mess up the GPS by injecting interference/noise into the screened
receiver ?)

There already is an aux power input for that battery at the interface,
4-35 volts, so obviously goes to a regulator. A better technical
solution would be for the firmware to use a few bits of the non-volatile
memory on board to prevent the time from going backwards, but that's not
going to happen.

Given that the old GPS-NAV models never have produced valid IGC files, I
would expect the cost of trying to do hardware modifications would exceed
any reasonable valuation of what they're currently worth. The brain
damage of trying to get OLC to accept the files has to be figured in
there somewhere.

Similarly, the 302 has had chronic data corruption issues in the flash
that were never fixed, so dropping $350+ today to swap out engines is
really hard to justify. But there's credible information that the black-
case models of those already have the newer engine, and may well be good
for a number of additional years.

-Dave