A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Implausible Time Records



 
 
Thread Tools Display Modes
  #11  
Old May 6th 19, 05:04 PM posted to rec.aviation.soaring
Tim Newport-Peace[_6_]
external usenet poster
 
Posts: 65
Default Implausible Time Records

Not necessarily related, but I noticed that your Firmware is dated
10-Feb-2017. I feel sure that there have been updates since then.

At 15:08 06 May 2019, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges out to
about 400 nm.Â* Moriarty is well within that area.Â* I've asked other
local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.Â* I'll take a look


at a divider for everything except the ADS-B WAAS GPS.Â* Its antenna is
mounted aft of the engine in the Stemme.Â* The rest are on or under the
glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my

ClearNav
screen went white with the caption (something like) No GPS.Â* Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS".Â* The
PowerFlarm portable screen also went blank with a "Zero satellites"

message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the time.

After B190339 the time jumps back to B190337, which is odd, and

leads
to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in future by
setting a longer fix interval, even 2 seconds might help, but no

promises.

I am not seeing any GPS outage around that time. This would be shown

by
the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to happen

as
you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that it

is
odd
and it might be.

Tim.
--
Dan, 5J

That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has a

shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim


--
Dan, 5J


  #12  
Old May 6th 19, 05:07 PM posted to rec.aviation.soaring
Tim Newport-Peace[_6_]
external usenet poster
 
Posts: 65
Default Implausible Time Records

GPS signals are line-of-sight only, and as the problem ocurred at take-off,
the source would have to be very close, like visible.

At 15:44 06 May 2019, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a 400
nm radius. If you're getting bad time stamps just at liftoff, it's not
likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to be
working on.



On 5/6/19 9:08 AM, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges out to


about 400 nm.Â* Moriarty is well within that area.Â* I've asked other
local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.Â* I'll take a

look

at a divider for everything except the ADS-B WAAS GPS.Â* Its antenna is


mounted aft of the engine in the Stemme.Â* The rest are on or under the


glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my

ClearNav
screen went white with the caption (something like) No GPS.Â* Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS".Â* The
PowerFlarm portable screen also went blank with a "Zero satellites"
message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the time.

After B190339 the time jumps back toÂ* B190337, which is odd, and
leads to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in future

by
setting a longer fix interval, even 2 seconds might help, but no
promises.

I am not seeing any GPS outage around that time. This would be shown


by the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to happen
as you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that it
is odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has a
shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim





  #13  
Old May 6th 19, 05:32 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Implausible Time Records

I've also had drop outs with my Trig TN-70 and its antenna, though not
as often as with my soaring GPSs.

Yes, the wires are tiny, but it was pretty simple to desolder them from
the puck, clip the cable to length, strip, tin, and solder.Â* I did that
for 3 antennae and they generally work fine, but lately have acting up.

I'm looking at THESE
https://www.amazon.com/CIROCOMM-Antenna-Ceramic-25x25x2mm-Geekstory/dp/B078Y2WNY6?ref_=Oct_TopRatedC_3248676011_1&pf_rd_p =57ac2d87-b669-53fa-a2b6-2c15e8d66f28&pf_rd_s=merchandised-search-6&pf_rd_t=101&pf_rd_i=3248676011&pf_rd_m=ATVPDKIKX 0DER&pf_rd_r=GNQVSWJ3FAVNDTDDJJDS&pf_rd_r=GNQVSWJ3 FAVNDTDDJJDS&pf_rd_p=57ac2d87-b669-53fa-a2b6-2c15e8d66f28
as replacements.Â* Any comments?Â* I wonder if that IPEX connector is a
push fit on the built in SMA connectors on the devices.Â* I'm also
considering replacing the modified antennae with factory new units and
using the longer cables to mount them on opposite canopy rails in the
Stemme.Â* Those should be about a meter apart.

On 5/6/2019 9:44 AM, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a 400
nm radius.Â* If you're getting bad time stamps just at liftoff,Â* it's
not likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to be
working on.



On 5/6/19 9:08 AM, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges out
to about 400 nm.Â* Moriarty is well within that area.Â* I've asked
other local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.Â* I'll take a
look at a divider for everything except the ADS-B WAAS GPS.Â* Its
antenna is mounted aft of the engine in the Stemme. The rest are on
or under the glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my
ClearNav
screen went white with the caption (something like) No GPS. Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS". The
PowerFlarm portable screen also went blank with a "Zero satellites"
message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the time.

After B190339 the time jumps back toÂ* B190337, which is odd, and
leads to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in future by
setting a longer fix interval, even 2 seconds might help, but no
promises.

I am not seeing any GPS outage around that time. This would be
shown by the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to
happen as you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that
it is odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has a
shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim




--
Dan, 5J

  #14  
Old May 6th 19, 05:34 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Implausible Time Records

You're correct, Tim.Â* I just checked and the latest firmware for the
vario is dated 5/10/18.Â* I'll download that today.Â* Still, I'm getting
the same error message from OLC for the ClearNav II computer with the
latest firmware installed.

On 5/6/2019 10:04 AM, Tim Newport-Peace wrote:
Not necessarily related, but I noticed that your Firmware is dated
10-Feb-2017. I feel sure that there have been updates since then.

At 15:08 06 May 2019, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges out to
about 400 nm.ÂÂ* Moriarty is well within that area.ÂÂ* I've asked other
local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.ÂÂ* I'll take a look
at a divider for everything except the ADS-B WAAS GPS.ÂÂ* Its antenna is
mounted aft of the engine in the Stemme.ÂÂ* The rest are on or under the
glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my

ClearNav
screen went white with the caption (something like) No GPS.ÂÂ* Zero
satellites.ÂÂ* And the ClearNav vario said, "Warning no GPS".ÂÂ* The
PowerFlarm portable screen also went blank with a "Zero satellites"

message.
On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the time.

After B190339 the time jumps back to B190337, which is odd, and

leads
to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in future by
setting a longer fix interval, even 2 seconds might help, but no

promises.
I am not seeing any GPS outage around that time. This would be shown

by
the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to happen

as
you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that it

is
odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has a

shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim

--
Dan, 5J


--
Dan, 5J
  #15  
Old May 6th 19, 06:39 PM posted to rec.aviation.soaring
kinsell
external usenet poster
 
Posts: 546
Default Implausible Time Records

On 5/6/19 10:32 AM, Dan Marotta wrote:
I've also had drop outs with my Trig TN-70 and its antenna, though not
as often as with my soaring GPSs.


Do they correlate with the engine running? If so, might be ignition noise.



Yes, the wires are tiny, but it was pretty simple to desolder them from
the puck, clip the cable to length, strip, tin, and solder.Â* I did that
for 3 antennae and they generally work fine, but lately have acting up.


It's easy to overheat the dielectric in the coax, causing loss of signal
strength.



I'm looking at THESE
https://www.amazon.com/CIROCOMM-Antenna-Ceramic-25x25x2mm-Geekstory/dp/B078Y2WNY6?ref_=Oct_TopRatedC_3248676011_1&pf_rd_p =57ac2d87-b669-53fa-a2b6-2c15e8d66f28&pf_rd_s=merchandised-search-6&pf_rd_t=101&pf_rd_i=3248676011&pf_rd_m=ATVPDKIKX 0DER&pf_rd_r=GNQVSWJ3FAVNDTDDJJDS&pf_rd_r=GNQVSWJ3 FAVNDTDDJJDS&pf_rd_p=57ac2d87-b669-53fa-a2b6-2c15e8d66f28
as replacements.Â* Any comments?Â* I wonder if that IPEX connector is a
push fit on the built in SMA connectors on the devices.Â* I'm also
considering replacing the modified antennae with factory new units and
using the longer cables to mount them on opposite canopy rails in the
Stemme.Â* Those should be about a meter apart.

On 5/6/2019 9:44 AM, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a 400
nm radius.Â* If you're getting bad time stamps just at liftoff,Â* it's
not likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to be
working on.



On 5/6/19 9:08 AM, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges out
to about 400 nm.Â* Moriarty is well within that area.Â* I've asked
other local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.Â* I'll take a
look at a divider for everything except the ADS-B WAAS GPS.Â* Its
antenna is mounted aft of the engine in the Stemme. The rest are on
or under the glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my
ClearNav
screen went white with the caption (something like) No GPS. Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS". The
PowerFlarm portable screen also went blank with a "Zero satellites"
message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the time.

After B190339 the time jumps back toÂ* B190337, which is odd, and
leads to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in future by
setting a longer fix interval, even 2 seconds might help, but no
promises.

I am not seeing any GPS outage around that time. This would be
shown by the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to
happen as you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that
it is odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has a
shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim



--
Dan, 5J


  #16  
Old May 6th 19, 11:20 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Implausible Time Records

These dropouts never occur during engine run which normally only runs 10
minutes or less from engine start to shutdown after takeoff.

Heating up the dielectric is something I didn't consider.Â* Maybe I
should replace the antennae...

On 5/6/2019 11:39 AM, kinsell wrote:
On 5/6/19 10:32 AM, Dan Marotta wrote:
I've also had drop outs with my Trig TN-70 and its antenna, though
not as often as with my soaring GPSs.


Do they correlate with the engine running?Â* If so, might be ignition
noise.



Yes, the wires are tiny, but it was pretty simple to desolder them
from the puck, clip the cable to length, strip, tin, and solder.Â* I
did that for 3 antennae and they generally work fine, but lately have
acting up.


It's easy to overheat the dielectric in the coax, causing loss of
signal strength.



I'm looking at THESE
https://www.amazon.com/CIROCOMM-Antenna-Ceramic-25x25x2mm-Geekstory/dp/B078Y2WNY6?ref_=Oct_TopRatedC_3248676011_1&pf_rd_p =57ac2d87-b669-53fa-a2b6-2c15e8d66f28&pf_rd_s=merchandised-search-6&pf_rd_t=101&pf_rd_i=3248676011&pf_rd_m=ATVPDKIKX 0DER&pf_rd_r=GNQVSWJ3FAVNDTDDJJDS&pf_rd_r=GNQVSWJ3 FAVNDTDDJJDS&pf_rd_p=57ac2d87-b669-53fa-a2b6-2c15e8d66f28
as replacements.Â* Any comments?Â* I wonder if that IPEX connector is a
push fit on the built in SMA connectors on the devices. I'm also
considering replacing the modified antennae with factory new units
and using the longer cables to mount them on opposite canopy rails in
the Stemme.Â* Those should be about a meter apart.

On 5/6/2019 9:44 AM, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a
400 nm radius.Â* If you're getting bad time stamps just at liftoff,Â*
it's not likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to
be working on.



On 5/6/19 9:08 AM, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges
out to about 400 nm.Â* Moriarty is well within that area.Â* I've
asked other local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.Â* I'll take a
look at a divider for everything except the ADS-B WAAS GPS.Â* Its
antenna is mounted aft of the engine in the Stemme. The rest are on
or under the glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my
ClearNav
screen went white with the caption (something like) No GPS. Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS". The
PowerFlarm portable screen also went blank with a "Zero
satellites" message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the
time.

After B190339 the time jumps back toÂ* B190337, which is odd, and
leads to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in
future by
setting a longer fix interval, even 2 seconds might help, but no
promises.

I am not seeing any GPS outage around that time. This would be
shown by the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to
happen as you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that
it is odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has
a shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim



--
Dan, 5J



--
Dan, 5J
  #17  
Old May 7th 19, 09:21 AM posted to rec.aviation.soaring
Tim Newport-Peace[_6_]
external usenet poster
 
Posts: 65
Default Implausible Time Records

Returning to the original problem, the warning from OLC is not particularly
helpful. The only problem detected was the out-of-sequence times. If these
were caused by corruption of the GPS signal, it should not affect the time
record. A failure of GPS signal will be shown in the IGC file as a zero GPS
altitude. This is not the case, therefore we can take it that it is not a
GPS problem.

As the time error occurred during take-off, when the glider was only a few
feet AGL, it was long before the start of the ‘Soaring Performance’, so
OLC is being a bit pedantic. I very much doubt if a Badge Claim would have
noticed this. SeeYou just skips over it.

I see this as a problem owned by ClearNav, although I have seen similar
time sequence errors in other recorders over the years. It will be
interesting to see if it reappears with the latest firmware.

Tim.
--
At 22:20 06 May 2019, Dan Marotta wrote:
These dropouts never occur during engine run which normally only runs 10
minutes or less from engine start to shutdown after takeoff.

Heating up the dielectric is something I didn't consider.Â* Maybe I
should replace the antennae...

On 5/6/2019 11:39 AM, kinsell wrote:
On 5/6/19 10:32 AM, Dan Marotta wrote:
I've also had drop outs with my Trig TN-70 and its antenna, though
not as often as with my soaring GPSs.


Do they correlate with the engine running?Â* If so, might be ignition
noise.



Yes, the wires are tiny, but it was pretty simple to desolder them
from the puck, clip the cable to length, strip, tin, and solder.Â* I
did that for 3 antennae and they generally work fine, but lately have
acting up.


It's easy to overheat the dielectric in the coax, causing loss of
signal strength.




On 5/6/2019 9:44 AM, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a
400 nm radius.Â* If you're getting bad time stamps just at liftoff,Â*


it's not likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to
be working on.




  #18  
Old May 7th 19, 03:21 PM posted to rec.aviation.soaring
kinsell
external usenet poster
 
Posts: 546
Default Implausible Time Records

Looking at your flight logs on OLC, you have the last two that didn't
validate, but others earlier this year that did.

However, most of the altitude graphs are plotted with many hours of dead
time, with the flight being compressed into the very right hand part of
the graph. A very bizarre presentation.

Perhaps your ClearNav has a hardware fault that is gradually getting worse?



On 5/6/19 4:20 PM, Dan Marotta wrote:
These dropouts never occur during engine run which normally only runs 10
minutes or less from engine start to shutdown after takeoff.

Heating up the dielectric is something I didn't consider.Â* Maybe I
should replace the antennae...

On 5/6/2019 11:39 AM, kinsell wrote:
On 5/6/19 10:32 AM, Dan Marotta wrote:
I've also had drop outs with my Trig TN-70 and its antenna, though
not as often as with my soaring GPSs.


Do they correlate with the engine running?Â* If so, might be ignition
noise.



Yes, the wires are tiny, but it was pretty simple to desolder them
from the puck, clip the cable to length, strip, tin, and solder.Â* I
did that for 3 antennae and they generally work fine, but lately have
acting up.


It's easy to overheat the dielectric in the coax, causing loss of
signal strength.



I'm looking at THESE
https://www.amazon.com/CIROCOMM-Antenna-Ceramic-25x25x2mm-Geekstory/dp/B078Y2WNY6?ref_=Oct_TopRatedC_3248676011_1&pf_rd_p =57ac2d87-b669-53fa-a2b6-2c15e8d66f28&pf_rd_s=merchandised-search-6&pf_rd_t=101&pf_rd_i=3248676011&pf_rd_m=ATVPDKIKX 0DER&pf_rd_r=GNQVSWJ3FAVNDTDDJJDS&pf_rd_r=GNQVSWJ3 FAVNDTDDJJDS&pf_rd_p=57ac2d87-b669-53fa-a2b6-2c15e8d66f28
as replacements.Â* Any comments?Â* I wonder if that IPEX connector is a
push fit on the built in SMA connectors on the devices. I'm also
considering replacing the modified antennae with factory new units
and using the longer cables to mount them on opposite canopy rails in
the Stemme.Â* Those should be about a meter apart.

On 5/6/2019 9:44 AM, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a
400 nm radius.Â* If you're getting bad time stamps just at liftoff,
it's not likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to
be working on.



On 5/6/19 9:08 AM, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges
out to about 400 nm.Â* Moriarty is well within that area.Â* I've
asked other local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship.Â* I'll take a
look at a divider for everything except the ADS-B WAAS GPS.Â* Its
antenna is mounted aft of the engine in the Stemme. The rest are on
or under the glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my
ClearNav
screen went white with the caption (something like) No GPS. Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS". The
PowerFlarm portable screen also went blank with a "Zero
satellites" message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the
time.

After B190339 the time jumps back toÂ* B190337, which is odd, and
leads to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in
future by
setting a longer fix interval, even 2 seconds might help, but no
promises.

I am not seeing any GPS outage around that time. This would be
shown by the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to
happen as you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just that
it is odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna has
a shortened cable to a MECA divider, then a short SMA-SMA link cable.
Jim



--
Dan, 5J




  #19  
Old May 7th 19, 04:07 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Implausible Time Records

Another thought:Â* Richard Kellerman advised me to snug the connectors
with a wrench.Â* Mine are probably only hand tight. Another small task...

On 5/6/2019 4:20 PM, Dan Marotta wrote:
These dropouts never occur during engine run which normally only runs
10 minutes or less from engine start to shutdown after takeoff.

Heating up the dielectric is something I didn't consider.Â* Maybe I
should replace the antennae...

On 5/6/2019 11:39 AM, kinsell wrote:
On 5/6/19 10:32 AM, Dan Marotta wrote:
I've also had drop outs with my Trig TN-70 and its antenna, though
not as often as with my soaring GPSs.


Do they correlate with the engine running?Â* If so, might be ignition
noise.



Yes, the wires are tiny, but it was pretty simple to desolder them
from the puck, clip the cable to length, strip, tin, and solder.Â* I
did that for 3 antennae and they generally work fine, but lately
have acting up.


It's easy to overheat the dielectric in the coax, causing loss of
signal strength.



I'm looking at THESE
https://www.amazon.com/CIROCOMM-Antenna-Ceramic-25x25x2mm-Geekstory/dp/B078Y2WNY6?ref_=Oct_TopRatedC_3248676011_1&pf_rd_p =57ac2d87-b669-53fa-a2b6-2c15e8d66f28&pf_rd_s=merchandised-search-6&pf_rd_t=101&pf_rd_i=3248676011&pf_rd_m=ATVPDKIKX 0DER&pf_rd_r=GNQVSWJ3FAVNDTDDJJDS&pf_rd_r=GNQVSWJ3 FAVNDTDDJJDS&pf_rd_p=57ac2d87-b669-53fa-a2b6-2c15e8d66f28
as replacements.Â* Any comments?Â* I wonder if that IPEX connector is
a push fit on the built in SMA connectors on the devices. I'm also
considering replacing the modified antennae with factory new units
and using the longer cables to mount them on opposite canopy rails
in the Stemme.Â* Those should be about a meter apart.

On 5/6/2019 9:44 AM, kinsell wrote:
Jamming is directed skyward, they're not taking out car gps's in a
400 nm radius.Â* If you're getting bad time stamps just at liftoff,Â*
it's not likely caused by jamming.

I'm suspicious of your cut-down gps cables, those are tiny wires to
be working on.



On 5/6/19 9:08 AM, Dan Marotta wrote:
Yes, the GPS jamming usually centers around Alamogordo and ranges
out to about 400 nm. Moriarty is well within that area.Â* I've
asked other local pilots and they don't report so many drop outs.

Maybe there are just too many GPS antennae in my ship. I'll take a
look at a divider for everything except the ADS-B WAAS GPS.Â* Its
antenna is mounted aft of the engine in the Stemme. The rest are
on or under the glare shield.

On 5/5/2019 7:42 PM, JS wrote:
On Sunday, May 5, 2019 at 3:43:24 PM UTC-7, Dan Marotta wrote:
Thanks Tim

I'll increase my time interval to 2 seconds and see if that helps.

Strange that the igc file does not show GPS drop outs since my
ClearNav
screen went white with the caption (something like) No GPS. Zero
satellites.Â* And the ClearNav vario said, "Warning no GPS". The
PowerFlarm portable screen also went blank with a "Zero
satellites" message.

On 5/5/2019 1:05 PM, Tim Newport-Peace wrote:
Dan,

Open your file with a text editor and search for "B190338"
This will put you in the right area.
In each record, after the letter B, the next six bytes are the
time.

After B190339 the time jumps back toÂ* B190337, which is odd,
and leads to
there being two records with a time of 190338, and also 190339.

Odd, but I have seen this before. Maybe you can avoid it in
future by
setting a longer fix interval, even 2 seconds might help, but
no promises.

I am not seeing any GPS outage around that time. This would be
shown by the
Letter "A" in the 25th byte changing to a "V".

Although it does not help a lot, the sequence error seems to
happen as you
left the ground, so I guess you were not reversing turns?

I'm not saying this is what OLC are complaining about, just
that it is odd
and it might be.

Tim.
--
Dan, 5J
That smells of GPS jamming.
Check this page.
https://www.navcen.uscg.gov/pdf/gps/...terference.pdf
I did not have a problem with the vario file today. My antenna
has a shortened cable to a MECA divider, then a short SMA-SMA
link cable.
Jim



--
Dan, 5J




--
Dan, 5J
  #20  
Old May 7th 19, 04:13 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Implausible Time Records

No help from ClearNav (yet).Â* I've updated the CNvXC firmware but not
flown with it yet.Â* It's overcast here...Â* As stated elsewhere, I'll
snug the connectors with a wrench (spanner), and I've relocated the
antenna pucks further apart, though a local pilot tells me he has four
antennae lined up next to each other and has no problems with reception.

Elsewhere I said that I don't have drop outs with the engine running.Â*
That was not entirely true.Â* I've had drop outs during repositioning
flights over the Rocky Mountains at 18,000' MSL.Â* It's very annoying but
I can see where I'm going and I'm not scoring those flights.

If I lose any more flights, I'll have to buy new antennae...

On 5/7/2019 2:21 AM, Tim Newport-Peace wrote:
Returning to the original problem, the warning from OLC is not particularly
helpful. The only problem detected was the out-of-sequence times. If these
were caused by corruption of the GPS signal, it should not affect the time
record. A failure of GPS signal will be shown in the IGC file as a zero GPS
altitude. This is not the case, therefore we can take it that it is not a
GPS problem.

As the time error occurred during take-off, when the glider was only a few
feet AGL, it was long before the start of the ‘Soaring Performance’, so
OLC is being a bit pedantic. I very much doubt if a Badge Claim would have
noticed this. SeeYou just skips over it.

I see this as a problem owned by ClearNav, although I have seen similar
time sequence errors in other recorders over the years. It will be
interesting to see if it reappears with the latest firmware.

Tim.


--
Dan, 5J
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
All US Records are Now Motor Glider Records Tango Eight Soaring 99 March 23rd 17 01:07 PM
OT 4 airport round robin - time lapsed / real time with ATC COMS -video A Lieberma[_2_] Owning 0 August 30th 09 12:26 AM
OT 4 airport round robin - time lapsed / real time with ATC COMS -video [email protected] Instrument Flight Rules 0 August 30th 09 12:26 AM
4 airport round robin - time lapsed / real time with ATC COMS - video [email protected] Piloting 0 August 30th 09 12:25 AM
they took me back in time and the nsa or japan wired my head and now they know the idea came from me so if your back in time and wounder what happen they change tim liverance history for good. I work at rts wright industries and it a time travel trap tim liverance Military Aviation 0 August 18th 03 12:18 AM


All times are GMT +1. The time now is 05:32 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.