ADS-B suppression question

[clam]

Wondering if someone can explain to me...
The portable ADS-B receivers generally function via Bluetooth or WiFi to a display. Most transponders, if not all, need a hardwired suppression line input for an ADS-B installation. Is this possible with the portables?

Specifically, I have the Trig TT22 transponder and was looking at the Dual XGPS170 UAT. The display is GRT HXr which has bluetooth capability.

[cfiidon]

You'd have to contact the makers of your DualXGPS170 to see how they handle suppression of ownship. A receiver could ignore a nearby high power transmission but when you receive the uplink TIS target I have no idea how they discriminate and not show a target under/over you all the time.

You are correct in that your transponder has a hardwired suppression line for that.

By the way, you used the term UAT which stands for Universal Access Transceiver. This term applies to ADS-B In/Out systems, not simply receivers such as the DualXGPS170.

Don

[jclark]

Originally Posted by clam

Wondering if someone can explain to me...
The portable ADS-B receivers generally function via Bluetooth or WiFi to a display. Most transponders, if not all, need a hardwired suppression line input for an ADS-B installation. Is this possible with the portables?

Specifically, I have the Trig TT22 transponder and was looking at the Dual XGPS170 UAT. The display is GRT HXr which has bluetooth capability.

The DUAL XGPS170 ADS-B receiver can supply the data to the GRT HXr via **USB**. You will want to get a powered USB hub so that you have enough ports for other Bluetooth stuff and your memory stick. The hub is *required* for the SX series.

Now, when you connect via the USB port, the HXr will recognize the DUAL. You will need to have USB ADS-B turned "ON" via setup of the HXr.

You will also need to add your "N" number and the OCTAL registration number from the FAA (converted to HEX) to the HXr in setup. The Trig TT22 will have this info as well.

When the Trig "squits" your info (n-number, registration number, altitude, speed etc) and that info get broadcast to the aerial world, you HXr will say "Oh!, that me. I don't need to put that on the screen nor do I have a traffic alert!"

Bluetooth on the DUAL is used to connect to you iPad or Android tablet or phone running your favorite compatible app.

Bluetooth on the GRT is used to connect to your Android tablet or phone running the GRT app.

Hope this helps. More info is on the GRT site.
Feel free to "holler" if there are further questions as I am the one who did initial field test of this combination.

James
p.s. The same process works for other compatible receivers e.g. the iLevil and the SkyRadar

[clam]

thanks gents ... James, one last question then, the TT22 will have only the power/ground and the pin 2 and 3 serial connections then, correct? (pin 2 & 3 providing encoder information). I guess the Dual XGPS will provide GPS data for ADS-B solution via the USB line as well (albeit non-2020 mandate compliant)?

[jclark]

Originally Posted by clam

thanks gents ... James, one last question then, the TT22 will have only the power/ground and the pin 2 and 3 serial connections then, correct? (pin 2 & 3 providing encoder information). I guess the Dual XGPS will provide GPS data for ADS-B solution via the USB line as well (albeit non-2020 mandate compliant)?

The DUAL does NOT supply the GPS position info to the "system" in this case.
Position info is provided by a WAAS GPS via the serial line. This info can come from the HXr or even a 496 (for now, albeit not compliant with 2020 mandate).

You will need to specify to the TT-22 the level of integrity/accuracy of the position source that you have.

If you use the TT-22 control head (2 1/4") then THAT provides encoder info. Otherwise the HXr will need to do so.

I have assisted with TT-31 and TT-22 hookups this way.

Again, the DUAL is only a "receiver" in this mode. It does provide GPS position data to the iPad or Android devices though.


James

[clam]

... I am feeding the HXr gps data with a Garmin 300XL via ARINC 429 bus. Will the HXr be able to send that data to the TT22 through the serial connections (pin 2 & 3 of the TT22) or will I need a dedicated GPS input to the TT22?

The TT22 manual and wiring pinout (note #2 on the GRT TT22 adapter pinout) make it sound like the GPS data in feed will work this way.

Thanks a ton for your help. This is the last bit of avionics wiring I'm trying to finish up.

[jclark]

Originally Posted by clam

... I am feeding the HXr gps data with a Garmin 300XL via ARINC 429 bus. Will the HXr be able to send that data to the TT22 through the serial connections (pin 2 & 3 of the TT22) or will I need a dedicated GPS input to the TT22?

The TT22 manual and wiring pinout (note #2 on the GRT TT22 adapter pinout) make it sound like the GPS data in feed will work this way.

Thanks a ton for your help. This is the last bit of avionics wiring I'm trying to finish up.

You should be able to use one of your serial ports OUT to send GPS position data to the TT-22 as I think that is what we did on Widget's system. He has the 300XL + HXr + TT-31.

NOTE: This discussion *probably* should move over to the GRT Forum or to email to me or GRT as it is not "RV-specific" (though very much RV related).

James