GPS Nav question ....

I have been using a GPS Nav and L-Nav combination for a year or so, it
came with the glider I procured.

Yesterday I lost GPS reception from GPS Nav, first time this has
occurred. Wondering what I should try or look for.

- Unit is mounted on the shelf behind the pilot in a ASW-20
- nothing covering it
- Camelback bladder placed next to it
- Unit was re-calibrated last year
- new internal battery installed last year
- hardware version 38
- software version 5.1
- Cambridge Aero explorer plus says voltage of internal battery 3.0
volts
- glider battery was reading 12.8 volts at time of lost reception.
- SeeYou would not download file from the device, it hung up
- Cambridge Aero Explorer Plus was able to down load the file just
fine

The only thing different in the cockpit was that I mounted my SPOT
device on my left parachute strap around chest height.

I do not see any parameters that allow me to reset the logger or
delete logs from it.

Any ideas or thoughts?

Ron Gleason

On 8/14/11 12:12 PM, Ron Gleason wrote:
I have been using a GPS Nav and L-Nav combination for a year or so, it
came with the glider I procured.

Yesterday I lost GPS reception from GPS Nav, first time this has
occurred. Wondering what I should try or look for.

- Unit is mounted on the shelf behind the pilot in a ASW-20
- nothing covering it
- Camelback bladder placed next to it
- Unit was re-calibrated last year
- new internal battery installed last year
- hardware version 38
- software version 5.1
- Cambridge Aero explorer plus says voltage of internal battery 3.0
volts
- glider battery was reading 12.8 volts at time of lost reception.
- SeeYou would not download file from the device, it hung up
- Cambridge Aero Explorer Plus was able to down load the file just
fine

The only thing different in the cockpit was that I mounted my SPOT
device on my left parachute strap around chest height.

I do not see any parameters that allow me to reset the logger or
delete logs from it.

Any ideas or thoughts?

Ron Gleason

Ron

When you say you lost reception just top clarify the L-NAV stopped
getting data in flight (and still now?) but the GPS-NAV has logged a CAI
file that is OK, you can download that file and it does not have data
gaps when you look at it in SeeYou or similar? and the file also passes
security tests?

If that is correct then my assumption would be the most likely problem
is just cabling between the L-NAV and GPS-NAV. If you exclude that then
you have a faulty GPS-NAV or L-NAV and swapping devices with somebody
else would be an easy way to test for that.

It is not uncommon with these boxes to have problems with wiring. These
devices are getting pretty old and possible issues including corrosion
broken pins or over-bent pins (esp. on telco jacks=sockets), and loose
pins or just broken wires in the plugs . Have a really good look at all
pins and connectors in the box and on the cable. If the cables are
suspect install new connectors and/or replace the cable.

Darryl

On Aug 14, 2:53*pm, Darryl Ramm wrote:
On 8/14/11 12:12 PM, Ron Gleason wrote:









I have been using a GPS Nav and L-Nav combination for a year or so, it
came with the glider I procured.

Yesterday I lost GPS reception from GPS Nav, first time this has
occurred. *Wondering what I should try or look for.

- *Unit is mounted on the shelf behind the pilot in a ASW-20
- *nothing covering it
- *Camelback bladder placed next to it
- *Unit was re-calibrated last year
- *new internal battery installed last year
- *hardware version 38
- *software version 5.1
- *Cambridge Aero explorer plus says voltage of internal battery 3.0
volts
- *glider battery was reading 12.8 volts at time of lost reception.
- *SeeYou would not download file from the device, it hung up
- *Cambridge Aero Explorer Plus was able to down load the file just
fine

The only thing different in the cockpit was that I mounted my SPOT
device on my left parachute strap around chest height.

I do not see any parameters that allow me to reset the logger or
delete logs from it.

Any ideas or thoughts?

Ron Gleason

Ron

When you say you lost reception just top clarify the L-NAV stopped
getting data in flight (and still now?) but the GPS-NAV has logged a CAI
file that is OK, you can download that file and it does not have data
gaps when you look at it in SeeYou or similar? and the file also passes
security tests?

If that is correct then my assumption would be the most likely problem
is just cabling between the L-NAV and GPS-NAV. If you exclude that then
you have a faulty GPS-NAV or L-NAV and swapping devices with somebody
else would be an easy way to test for that.

It is not uncommon with these boxes to have problems with wiring. These
devices are getting pretty old and possible issues including corrosion
broken pins or over-bent pins (esp. on telco jacks=sockets), and loose
pins or just broken wires in the plugs . Have a really good look at all
pins and connectors in the box and on the cable. If the cables are
suspect install new connectors and/or replace the cable.

Darryl

To clarify, the GPS NAV display stopped display values in data
fields. I tried a different TP and GO and still no data

The L-NAV displayed the message WAITING GPS or GPS WAITING

The CAI file stopped at the point in the flight where the GPS NAV data
fields disappeared.

The Oudie, stand alone, recorded the complete flight.

I have visually checked some of the wiring but will get the volt meter
or try it again next flight to see if it repeats.

Ron

On 8/14/11 2:57 PM, Ron Gleason wrote:
On Aug 14, 2:53 pm, Darryl wrote:
On 8/14/11 12:12 PM, Ron Gleason wrote:









I have been using a GPS Nav and L-Nav combination for a year or so, it
came with the glider I procured.

Yesterday I lost GPS reception from GPS Nav, first time this has
occurred. Wondering what I should try or look for.

- Unit is mounted on the shelf behind the pilot in a ASW-20
- nothing covering it
- Camelback bladder placed next to it
- Unit was re-calibrated last year
- new internal battery installed last year
- hardware version 38
- software version 5.1
- Cambridge Aero explorer plus says voltage of internal battery 3.0
volts
- glider battery was reading 12.8 volts at time of lost reception.
- SeeYou would not download file from the device, it hung up
- Cambridge Aero Explorer Plus was able to down load the file just
fine

The only thing different in the cockpit was that I mounted my SPOT
device on my left parachute strap around chest height.

I do not see any parameters that allow me to reset the logger or
delete logs from it.

Any ideas or thoughts?

Ron Gleason

Ron

When you say you lost reception just top clarify the L-NAV stopped
getting data in flight (and still now?) but the GPS-NAV has logged a CAI
file that is OK, you can download that file and it does not have data
gaps when you look at it in SeeYou or similar? and the file also passes
security tests?

If that is correct then my assumption would be the most likely problem
is just cabling between the L-NAV and GPS-NAV. If you exclude that then
you have a faulty GPS-NAV or L-NAV and swapping devices with somebody
else would be an easy way to test for that.

It is not uncommon with these boxes to have problems with wiring. These
devices are getting pretty old and possible issues including corrosion
broken pins or over-bent pins (esp. on telco jacks=sockets), and loose
pins or just broken wires in the plugs . Have a really good look at all
pins and connectors in the box and on the cable. If the cables are
suspect install new connectors and/or replace the cable.

Darryl

To clarify, the GPS NAV display stopped display values in data
fields. I tried a different TP and GO and still no data

The L-NAV displayed the message WAITING GPS or GPS WAITING

The CAI file stopped at the point in the flight where the GPS NAV data
fields disappeared.

The Oudie, stand alone, recorded the complete flight.

I have visually checked some of the wiring but will get the volt meter
or try it again next flight to see if it repeats.

Ron

Those modular telco connectors are especially suspect. I've had to both
(carefully) bend back up pins in a Model 25 socket so they made better
contact and cut off and replace the crimp on cable connectors. Sometimes
very subtle things happen with those, like the wire breaks inside or
just at the connector and it becomes intermittent. Try carefully flexing
the wires and pulling and pushing on them as you check with a multi-meter.

The GPS-NAV GPS status LED is a good clue. Is it illuminated at all?
Solid green (trying to get a fix) or blinking (has a fix, then something
downstream in the wiring or the rest of the GPS-NAV or LNAV is faulty).

Darryl

On Aug 14, 4:20*pm, Darryl Ramm wrote:
On 8/14/11 2:57 PM, Ron Gleason wrote:









On Aug 14, 2:53 pm, Darryl *wrote:
On 8/14/11 12:12 PM, Ron Gleason wrote:

I have been using a GPS Nav and L-Nav combination for a year or so, it
came with the glider I procured.

Yesterday I lost GPS reception from GPS Nav, first time this has
occurred. *Wondering what I should try or look for.

- *Unit is mounted on the shelf behind the pilot in a ASW-20
- *nothing covering it
- *Camelback bladder placed next to it
- *Unit was re-calibrated last year
- *new internal battery installed last year
- *hardware version 38
- *software version 5.1
- *Cambridge Aero explorer plus says voltage of internal battery 3.0
volts
- *glider battery was reading 12.8 volts at time of lost reception.
- *SeeYou would not download file from the device, it hung up
- *Cambridge Aero Explorer Plus was able to down load the file just
fine

The only thing different in the cockpit was that I mounted my SPOT
device on my left parachute strap around chest height.

I do not see any parameters that allow me to reset the logger or
delete logs from it.

Any ideas or thoughts?

Ron Gleason

Ron

When you say you lost reception just top clarify the L-NAV stopped
getting data in flight (and still now?) but the GPS-NAV has logged a CAI
file that is OK, you can download that file and it does not have data
gaps when you look at it in SeeYou or similar? and the file also passes
security tests?

If that is correct then my assumption would be the most likely problem
is just cabling between the L-NAV and GPS-NAV. If you exclude that then
you have a faulty GPS-NAV or L-NAV and swapping devices with somebody
else would be an easy way to test for that.

It is not uncommon with these boxes to have problems with wiring. These
devices are getting pretty old and possible issues including corrosion
broken pins or over-bent pins (esp. on telco jacks=sockets), and loose
pins or just broken wires in the plugs . Have a really good look at all
pins and connectors in the box and on the cable. If the cables are
suspect install new connectors and/or replace the cable.

Darryl

To clarify, the GPS NAV display stopped display values in data
fields. *I tried a different TP and GO and still no data

The L-NAV displayed the message WAITING GPS or GPS WAITING

The CAI file stopped at the point in the flight where the GPS NAV data
fields disappeared.

The Oudie, stand alone, recorded the complete flight.

I have visually checked some of the wiring but will get the volt meter
or try it again next flight to see if it repeats.

Ron

Those modular telco connectors are especially suspect. I've had to both
(carefully) bend back up pins in a Model 25 socket so they made better
contact and cut off and replace the crimp on cable connectors. Sometimes
very subtle things happen with those, like the wire breaks inside or
just at the connector and it becomes intermittent. Try carefully flexing
the wires and pulling and pushing on them as you check with a multi-meter..

The GPS-NAV GPS status LED is a good clue. Is it illuminated at all?
Solid green (trying to get a fix) or blinking (has a fix, then something
downstream in the wiring or the rest of the GPS-NAV or LNAV is faulty).

Darryl

Just brought it outside and plugged it, external power not in the
glider. Green light appeared and it started blinking a few minutes
later. Will be checking the connection to the display and L-NAV next.

Thanks for the hints and advice

On Aug 14, 4:32*pm, Ron Gleason wrote:
On Aug 14, 4:20*pm, Darryl Ramm wrote:





On 8/14/11 2:57 PM, Ron Gleason wrote:

On Aug 14, 2:53 pm, Darryl *wrote:
On 8/14/11 12:12 PM, Ron Gleason wrote:

I have been using a GPS Nav and L-Nav combination for a year or so, it
came with the glider I procured.

Yesterday I lost GPS reception from GPS Nav, first time this has
occurred. *Wondering what I should try or look for.

- *Unit is mounted on the shelf behind the pilot in a ASW-20
- *nothing covering it
- *Camelback bladder placed next to it
- *Unit was re-calibrated last year
- *new internal battery installed last year
- *hardware version 38
- *software version 5.1
- *Cambridge Aero explorer plus says voltage of internal battery 3.0
volts
- *glider battery was reading 12.8 volts at time of lost reception.