ADSB visibility with non certified GPS

On Monday, October 2, 2017 at 2:47:00 PM UTC-7, wrote:
On Sunday, October 1, 2017 at 4:24:46 PM UTC-5, Ramy wrote:
While we at it, will be good to know if we can connect any non TSO amplified GPS antenna to the TN72 and save an additional $300, and if anyone has a recommendation.

Ramy


I wondered about this too because the TA70 is HUGE and really designed for external mounting.

I also found this quote online related to the TN72. "Where a non-TSO antenna is used, the antenna must include an integral amplifier with gain of not less than 20dB."

Below are some code definitions, and then one data set each from a TN70 Antenna and then a GPS antenna borrowed from a CAI 302. I replaced my specific coordinates with "z", but the rest of the data looks to be there. I googled $RAIM, but didn't find anything on that other than it's related to GPS accuracy, etc.



$GPGGA - Global Positioning System Fix Data
$GPVTG - Track made good and ground speed
$GPGSA - GPS DOP and active satellites
$GPZDA - Date & Time
$GPGLL - Geographic position, latitude / longitude
$GPGSV - GPS Satellites in view
$GPRMC - Recommended minimum specific GPS/Transit data


TA70 Antenna
$RAIM,128443,103224,012335,012471,020000,020000,00 0887,000896,111,5,11111111*36
$GPGGA,202757.00,zzzz.zzzzz,N,zzzzz.zzzzz,W,1,06,2 .44,-8.2,M,,M,,*73
$ACVT,1,W,000012,N,000004,U,000014*53
$GPVTG,291.94,T,,M,0.026,N,0.048,K,A*32
$GPGSA,A,3,13,15,20,21,18,10,,,,,,,3.47,2.44,2.47, 1*13
$GPZDA,202757.00,02,10,2017,,*64
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,202757.00,A,A*7B
$GPGSV,2,1,06,13,35,048,33,15,68,069,49,20,50,033, 48,21,52,330,47,1*6D
$GPGSV,2,2,06,18,44,285,47,10,17,264,38,1*6B
$GPRMC,202758.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.04 4,261.96,021017,,,A,V*08

CAI 302 Antenna
$RAIM,150175,112197,013718,013213,020000,020000,00 2021,001947,111,5,11111111*31
$GPGGA,203009.00,zzzz.zzzz,N,zzzzz.zzzzz,W,1,06,2. 54,-10.0,M,,M,,*4E
$ACVT,1,E,000001,N,000004,U,000074*45
$GPVTG,14.73,T,,M,0.008,N,0.015,K,A*00
$GPGSA,A,3,20,13,15,18,21,10,,,,,,,3.53,2.54,2.45, 1*15
$GPZDA,203009.00,02,10,2017,,*69
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,203009.00,A,A*7C
$GPGSV,2,1,06,20,49,034,46,13,35,048,28,15,67,067, 46,18,44,286,48,1*66
$GPGSV,2,2,06,21,53,331,41,10,17,265,30,1*66
$GPRMC,203010.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.06 7,267.22,021017,,,A,V*0E

Is this from an NMEA data from a TN72? All the stuff you are looking at comes from whatever the antennas was connected to and you should not see any change there if both antennas are in the same nominal ballpark (i.e. can receive enough satellites for a fix etc.). But that won't totally prove the antenna is suitable or acceptable to the FAA.

As you point out "where a non-TSO antenna is used, the antenna must include an integral amplifier with gain of not less than 20dB." I expect a TSO antenna is required for install in certified gliders. That big blister hopefully can be hidden under a glareshield, or maybe not. Lots of stuff here needs clarity.

RAIM is Receiver Autonomous Integrity Monitoring. It is supported by GBS, GRS, GST etc. $RAIM isn't part of the NMEA 0183 spec, at least at v4.00.

Thanks Darryl.Â* I do compare my TT22's reported altitude with my
altimeter allowing for the local altimeter setting.

On 10/2/2017 11:50 AM, Darryl Ramm wrote:
On Monday, October 2, 2017 at 10:16:40 AM UTC-7, Dan Marotta wrote:
Thanks, Evan, but that does not answer the question, either.Â* Sure there
might be certificate action, should a pilot get caught turning on a
not-yet-tested/certified transponder, but it seems to me it would have
been better if the Hawker had gotten a RA from its TCAS box.Â* I know
it's a rhetorical question but then so are a lot of the FARs...Â* I'd
just prefer receiving a letter from the FAA over bailing out (or worse).

BTW, my transponder was checked by a certified technician within the
preceding 24 calendar months and complies with 91.413(c) and has a
proper logbook entry.

On 10/2/2017 10:26 AM, Tango Eight wrote:
On Monday, October 2, 2017 at 12:16:22 PM UTC-4, Dan Marotta wrote:
Didn't answer the question.

What harm could have come from turning on a not-yet-approved transponder?
Violation of FAR 91.413.

best,
Evan Ludeman / T8
--
Dan, 5J
Dan

Evan is pointing out what is believed to be the pilot's concern here.

My pragmatic safety focused answer is there was little reason not to turn that transponder on, and I would have. The 14 CFR Appendix F to Part 43, ATC Transponder Tests and Inspections required by 14 CFR 91.413(c) only test RF properties of the transponder. There are unlikely to be undetected problems with modern transponders that causes errors in operation or impact other airspace users. And a call to Reno Approach for a transponder check would have been good assurance that the basic transponder operations are working, a good idea on any new install. In some ways Appendix F seems to address concerns of older generation less reliable transponder technology, and specifically to look for know faults that do could impact operation and other users, so still useful to know that stuff is working, and still a 14CFR requirement and should be done.

One thing to note is Appendix F to Part 43 does not check altitude encoder accuracy. And that transponder reported altitude is key to interoperation with TCAS. It's a good idea to check the encoder altitude displayed on your transponder against the altimeter and other sources, or check in with ATC if the transponder does not have an encoder altitude display.

--
Dan, 5J

I saw one of those big "blisters" mounted on a shelf under the turtle
deck of a Stemme.Â* That's likely where mine will go, just aft of the
solar panels.

On 10/2/2017 4:12 PM, Darryl Ramm wrote:
On Monday, October 2, 2017 at 2:47:00 PM UTC-7, wrote:
On Sunday, October 1, 2017 at 4:24:46 PM UTC-5, Ramy wrote:
While we at it, will be good to know if we can connect any non TSO amplified GPS antenna to the TN72 and save an additional $300, and if anyone has a recommendation.

Ramy

I wondered about this too because the TA70 is HUGE and really designed for external mounting.

I also found this quote online related to the TN72. "Where a non-TSO antenna is used, the antenna must include an integral amplifier with gain of not less than 20dB."

Below are some code definitions, and then one data set each from a TN70 Antenna and then a GPS antenna borrowed from a CAI 302. I replaced my specific coordinates with "z", but the rest of the data looks to be there. I googled $RAIM, but didn't find anything on that other than it's related to GPS accuracy, etc.



$GPGGA - Global Positioning System Fix Data
$GPVTG - Track made good and ground speed
$GPGSA - GPS DOP and active satellites
$GPZDA - Date & Time
$GPGLL - Geographic position, latitude / longitude
$GPGSV - GPS Satellites in view
$GPRMC - Recommended minimum specific GPS/Transit data


TA70 Antenna
$RAIM,128443,103224,012335,012471,020000,020000,00 0887,000896,111,5,11111111*36
$GPGGA,202757.00,zzzz.zzzzz,N,zzzzz.zzzzz,W,1,06,2 .44,-8.2,M,,M,,*73
$ACVT,1,W,000012,N,000004,U,000014*53
$GPVTG,291.94,T,,M,0.026,N,0.048,K,A*32
$GPGSA,A,3,13,15,20,21,18,10,,,,,,,3.47,2.44,2.47, 1*13
$GPZDA,202757.00,02,10,2017,,*64
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,202757.00,A,A*7B
$GPGSV,2,1,06,13,35,048,33,15,68,069,49,20,50,033, 48,21,52,330,47,1*6D
$GPGSV,2,2,06,18,44,285,47,10,17,264,38,1*6B
$GPRMC,202758.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.04 4,261.96,021017,,,A,V*08

CAI 302 Antenna
$RAIM,150175,112197,013718,013213,020000,020000,00 2021,001947,111,5,11111111*31
$GPGGA,203009.00,zzzz.zzzz,N,zzzzz.zzzzz,W,1,06,2. 54,-10.0,M,,M,,*4E
$ACVT,1,E,000001,N,000004,U,000074*45
$GPVTG,14.73,T,,M,0.008,N,0.015,K,A*00
$GPGSA,A,3,20,13,15,18,21,10,,,,,,,3.53,2.54,2.45, 1*15
$GPZDA,203009.00,02,10,2017,,*69
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,203009.00,A,A*7C
$GPGSV,2,1,06,20,49,034,46,13,35,048,28,15,67,067, 46,18,44,286,48,1*66
$GPGSV,2,2,06,21,53,331,41,10,17,265,30,1*66
$GPRMC,203010.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.06 7,267.22,021017,,,A,V*0E
Is this from an NMEA data from a TN72? All the stuff you are looking at comes from whatever the antennas was connected to and you should not see any change there if both antennas are in the same nominal ballpark (i.e. can receive enough satellites for a fix etc.). But that won't totally prove the antenna is suitable or acceptable to the FAA.

As you point out "where a non-TSO antenna is used, the antenna must include an integral amplifier with gain of not less than 20dB." I expect a TSO antenna is required for install in certified gliders. That big blister hopefully can be hidden under a glareshield, or maybe not. Lots of stuff here needs clarity.

--
Dan, 5J

On Monday, October 2, 2017 at 2:47:00 PM UTC-7, wrote:
On Sunday, October 1, 2017 at 4:24:46 PM UTC-5, Ramy wrote:
While we at it, will be good to know if we can connect any non TSO amplified GPS antenna to the TN72 and save an additional $300, and if anyone has a recommendation.

Ramy


I wondered about this too because the TA70 is HUGE and really designed for external mounting.

I also found this quote online related to the TN72. "Where a non-TSO antenna is used, the antenna must include an integral amplifier with gain of not less than 20dB."

Below are some code definitions, and then one data set each from a TN70 Antenna and then a GPS antenna borrowed from a CAI 302. I replaced my specific coordinates with "z", but the rest of the data looks to be there. I googled $RAIM, but didn't find anything on that other than it's related to GPS accuracy, etc.



$GPGGA - Global Positioning System Fix Data
$GPVTG - Track made good and ground speed
$GPGSA - GPS DOP and active satellites
$GPZDA - Date & Time
$GPGLL - Geographic position, latitude / longitude
$GPGSV - GPS Satellites in view
$GPRMC - Recommended minimum specific GPS/Transit data


TA70 Antenna
$RAIM,128443,103224,012335,012471,020000,020000,00 0887,000896,111,5,11111111*36
$GPGGA,202757.00,zzzz.zzzzz,N,zzzzz.zzzzz,W,1,06,2 .44,-8.2,M,,M,,*73
$ACVT,1,W,000012,N,000004,U,000014*53
$GPVTG,291.94,T,,M,0.026,N,0.048,K,A*32
$GPGSA,A,3,13,15,20,21,18,10,,,,,,,3.47,2.44,2.47, 1*13
$GPZDA,202757.00,02,10,2017,,*64
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,202757.00,A,A*7B
$GPGSV,2,1,06,13,35,048,33,15,68,069,49,20,50,033, 48,21,52,330,47,1*6D
$GPGSV,2,2,06,18,44,285,47,10,17,264,38,1*6B
$GPRMC,202758.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.04 4,261.96,021017,,,A,V*08

CAI 302 Antenna
$RAIM,150175,112197,013718,013213,020000,020000,00 2021,001947,111,5,11111111*31
$GPGGA,203009.00,zzzz.zzzz,N,zzzzz.zzzzz,W,1,06,2. 54,-10.0,M,,M,,*4E
$ACVT,1,E,000001,N,000004,U,000074*45
$GPVTG,14.73,T,,M,0.008,N,0.015,K,A*00
$GPGSA,A,3,20,13,15,18,21,10,,,,,,,3.53,2.54,2.45, 1*15
$GPZDA,203009.00,02,10,2017,,*69
$GPGLL,zzzz.zzzzz,N,zzzzz.zzzzz,W,203009.00,A,A*7C
$GPGSV,2,1,06,20,49,034,46,13,35,048,28,15,67,067, 46,18,44,286,48,1*66
$GPGSV,2,2,06,21,53,331,41,10,17,265,30,1*66
$GPRMC,203010.00,A,zzzz.zzzzz,N,zzzzz.zzzzz,W,0.06 7,267.22,021017,,,A,V*0E



I recently setup a system for a customer and tested on the bench. Trig TT22, TN72, tested with both TA70 antenna and a PowerFlarm GPS antenna it worked with either antenna and showed as a glider on a PowerFlarm in my shop.



Richard
www.craggyaero.com