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