Two L-NAV Questions

1. We have an older (Model 20) L-NAV that suddenly started reading ca.
2 - 2.5 kts "pessimistic". This started, perhaps coincidentally,
perhaps not, right after we'd had it at a public display, making us
wonder if perhaps someone accidentally tinkered with some of the
settings. We went back to the manual and checked all the calibration
screens, and couldn't detect anything wrong. Any ideas about what
might cause this instrument to suddenly start reading "low"?? FWIW,
with the power on and sitting on the ground, the vario reads ca. 3 kts
down, and the averager says -2.8.

2. Our old PC laptop at the field has died. Can't find the source of
new Cambridge software to download to another PC or, better yet, to
one of our Mac laptops. Again, anyone have a link to this software?

Jim Kellett

On Jul 21, 9:45*pm, Jim Kellett wrote:
1. We have an older (Model 20) L-NAV that suddenly started reading ca.
2 - 2.5 kts "pessimistic". *This started, perhaps coincidentally,
perhaps not, right after we'd had it at a public display, making us
wonder if perhaps someone accidentally tinkered with some of the
settings. * We went back to the manual and checked all the calibration
screens, and couldn't detect anything wrong. *Any ideas about what
might cause this instrument to suddenly start reading "low"?? *FWIW,
with the power on and sitting on the ground, the vario reads ca. 3 kts
down, and the averager says -2.8.

2. Our old PC laptop at the field has died. *Can't find the source of
new Cambridge software to download to another PC or, better yet, to
one of our Mac laptops. *Again, anyone have a link to this software?

Jim Kellett

What software is it that you need?
Fred Blair

On Jul 21, 10:45*pm, Jim Kellett wrote:
1. We have an older (Model 20) L-NAV that suddenly started reading ca.
2 - 2.5 kts "pessimistic". *This started, perhaps coincidentally,
perhaps not, right after we'd had it at a public display, making us
wonder if perhaps someone accidentally tinkered with some of the
settings. * We went back to the manual and checked all the calibration
screens, and couldn't detect anything wrong. *Any ideas about what
might cause this instrument to suddenly start reading "low"?? *FWIW,
with the power on and sitting on the ground, the vario reads ca. 3 kts
down, and the averager says -2.8.

2. Our old PC laptop at the field has died. *Can't find the source of
new Cambridge software to download to another PC or, better yet, to
one of our Mac laptops. *Again, anyone have a link to this software?

Jim Kellett

I'm sure an email to Gary Kamerer at Nielsen Kellerman will yield the
right answer, but in my experience, this is usually the sign of Bad
Things to come. You can start with the Calibrate function and try
to get the offset back to zero, by my guess is that you will run out
of adjustment. Here's the text from the manual on this:

e. [Variometer]
This screen shows the Variometer A/D reading. With no lift or sink,
the reading should be 511.
If is not, you may add or subtract an offset with the UP or DOWN arrow
keys. If the offset is
more than 40 counts, consider sending your unit to Cambridge over the
winter.

When this happened to me in the past, it required swapping out of one
of the main bits of magic.

P3

Hi Jim,

I recommend you call Gary Kammerer at NK for help with the L-NAV.
http://www.nkhome.com/support/cambridge.html

There are links to Cambridge software (for GPS-NAV) at the bottom of the
page he
http://www.cumulus-soaring.com/cai_gps-nav.htm

Software for the Cambridge 302 is available he
http://www.cumulus-soaring.com/cai_downloads.htm

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"Jim Kellett" wrote in message
...
1. We have an older (Model 20) L-NAV that suddenly started reading ca.
2 - 2.5 kts "pessimistic". This started, perhaps coincidentally,
perhaps not, right after we'd had it at a public display, making us
wonder if perhaps someone accidentally tinkered with some of the
settings. We went back to the manual and checked all the calibration
screens, and couldn't detect anything wrong. Any ideas about what
might cause this instrument to suddenly start reading "low"?? FWIW,
with the power on and sitting on the ground, the vario reads ca. 3 kts
down, and the averager says -2.8.

2. Our old PC laptop at the field has died. Can't find the source of
new Cambridge software to download to another PC or, better yet, to
one of our Mac laptops. Again, anyone have a link to this software?

Jim Kellett

In article
,
Papa3 wrote:

I'm sure an email to Gary Kamerer at Nielsen Kellerman will yield the
right answer, but in my experience, this is usually the sign of Bad
Things to come. You can start with the Calibrate function and try
to get the offset back to zero, by my guess is that you will run out
of adjustment. Here's the text from the manual on this:

e. [Variometer]
This screen shows the Variometer A/D reading. With no lift or sink,
the reading should be 511.
If is not, you may add or subtract an offset with the UP or DOWN arrow
keys. If the offset is
more than 40 counts, consider sending your unit to Cambridge over the
winter.

When this happened to me in the past, it required swapping out of one
of the main bits of magic.

I'm Jim's partner, and I just wanted to let you know that this was it. I
popped into this screen and the offset was set to about -50 and the A/D
reading was way down in the 400s somewhere. Bringing the offset back up
to 0 got the A/D reading right to the intended 511 mark and the vario
subsequently worked just great all day today. We have no idea how it got
set to -50 in the first place, but that it works now is the important
part. Thank you very much for this suggestion!

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

Great news....

I suggest you replace the internal battery inside the L-Nav. When this
gets low the unit will do all sorts of funny things. The L-Nav needs
this voltage to retain the proper settings. It's just a watch battery
that you can get at most drug stores.

Regards,
Pat Russette "CQ"

Mike Ash wrote:
In article
,
Papa3 wrote:

I'm sure an email to Gary Kamerer at Nielsen Kellerman will yield the
right answer, but in my experience, this is usually the sign of Bad
Things to come. You can start with the Calibrate function and try
to get the offset back to zero, by my guess is that you will run out
of adjustment. Here's the text from the manual on this:

e. [Variometer]
This screen shows the Variometer A/D reading. With no lift or sink,
the reading should be 511.
If is not, you may add or subtract an offset with the UP or DOWN arrow
keys. If the offset is
more than 40 counts, consider sending your unit to Cambridge over the
winter.

When this happened to me in the past, it required swapping out of one
of the main bits of magic.

I'm Jim's partner, and I just wanted to let you know that this was it. I
popped into this screen and the offset was set to about -50 and the A/D
reading was way down in the 400s somewhere. Bringing the offset back up
to 0 got the A/D reading right to the intended 511 mark and the vario
subsequently worked just great all day today. We have no idea how it got
set to -50 in the first place, but that it works now is the important
part. Thank you very much for this suggestion!