What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

GDL 82 Annunciator Requirement?

noelf

Well Known Member
I am helping a friend install a GDL 82 with his GTX 327 transponder. The installation manual shows an optional connection for an ADS-B OUT FAIL lamp. Is this really optional, or is it required to have this lamp as part of this configuration?
I seem to recall that when I read the multi-page FAA publication for the ADS-B equipment requirements (a few years ago) that an external FAIL indicator was required if the installation did not provide another means of indicating a failure of the ADS-B system. I also know that some of the L3 equipment requires this FAIL lamp.
Have the requirements changed such that this FAIL lamp is no longer required?
 
According to the installation manual, the Fail lamp, as well as the anonymous mode switch, are optional. I've done 6 GDL-82s, and only put the lamp in two of them
 
. I also know that some of the L3 equipment requires this FAIL lamp.
Have the requirements changed such that this FAIL lamp is no longer required?
Optional on the L3 Lynx NGT-9000 also.
Mainly intended for installations where the pilot does not have direct line of sight to the unit.
 
I installed the anonymous mode switch, but not the fail light. To ensure that the unit is working properly I request a PAPR every month or so.
 
I did not install the light as it says optional.
I check every flight that it is working by looking at my ADSB In display and see if I show up.
 
GDL 82 Fault Indicator

I am helping a friend install a GDL 82 with his GTX 327 transponder. The installation manual shows an optional connection for an ADS-B OUT FAIL lamp. Is this really optional, or is it required to have this lamp as part of this configuration?
I seem to recall that when I read the multi-page FAA publication for the ADS-B equipment requirements (a few years ago) that an external FAIL indicator was required if the installation did not provide another means of indicating a failure of the ADS-B system. I also know that some of the L3 equipment requires this FAIL lamp.
Have the requirements changed such that this FAIL lamp is no longer required?

Good Afternoon,

This will be optional in your installation. The fault lamp is inactive when ADS-B Out messages are providing all FAA required information, and active when the system is not transmitting all FAA required information.

Please let us know if you have any other questions.

Thanks,

Justin
 
Good Afternoon,

This will be optional in your installation. The fault lamp is inactive when ADS-B Out messages are providing all FAA required information, and active when the system is not transmitting all FAA required information.

Please let us know if you have any other questions.

Thanks,

Justin
Is that basically a repeater of what you would see with a laptop hooked up and looking at the Faults page? Any red kicks it on?

They make a little bulkhead USB fitting which would make a sharp looking test port for a blind mounted GDL82 box.
 
I put in both the anon switch and the fail led. I would want to know ASAP if the system was not working. Why wait on a PAPR report? And the anon mode might be desired sometime. IMHO Makes sense to put them both in. Yes they are legally optional, but not that much trouble to install.
 
In the GDL-82 installation manual, I read this:

"4.5.1 L-Band
The following provides guidance for selecting an optimal location for L-Band antenna installation. The GDL 82 introduces 1.5 dB of loss to the transmission line between the interfaced transponder and the L-Band antenna. The GDL 82 should be mounted as close as possible to the antenna to reduce the length of coaxial cable between the unit and the antenna."

What kinds of distances are we talking? Does it need to be within 2 inches?
Or are they talking many feet?

The installation I have in mind would put the coax length at ~2.5 - 3 feet. Is that too long? I'm using RG-400.
 
I did...

I installed the anonymous switch and annunciator light with a single three way micro toggle switch.

Nice to know when it's not transmitting properly...usually when I forget to put the transponder in ALT before takeoff! ;)

I am helping a friend install a GDL 82 with his GTX 327 transponder. The installation manual shows an optional connection for an ADS-B OUT FAIL lamp. Is this really optional, or is it required to have this lamp as part of this configuration?
I seem to recall that when I read the multi-page FAA publication for the ADS-B equipment requirements (a few years ago) that an external FAIL indicator was required if the installation did not provide another means of indicating a failure of the ADS-B system. I also know that some of the L3 equipment requires this FAIL lamp.
Have the requirements changed such that this FAIL lamp is no longer required?
 
I
..usually when I forget to put the transponder in ALT before takeoff! ;)

The current faa recommendation (rule?) is to run transponders on alt 100% of the time, no longer just prior to takeoff. Set it to ALT and leave it, never touch it again.
 
Yeah I'll do that going forward...just used to putting it in standby because I fly for work 100% internationally and the airports I frequent still work the old way.

And also...old dogs and new tricks. LOL

The current faa recommendation (rule?) is to run transponders on alt 100% of the time, no longer just prior to takeoff. Set it to ALT and leave it, never touch it again.
 
GDL 82 Insertion

In the GDL-82 installation manual, I read this:

"4.5.1 L-Band
The following provides guidance for selecting an optimal location for L-Band antenna installation. The GDL 82 introduces 1.5 dB of loss to the transmission line between the interfaced transponder and the L-Band antenna. The GDL 82 should be mounted as close as possible to the antenna to reduce the length of coaxial cable between the unit and the antenna."

What kinds of distances are we talking? Does it need to be within 2 inches?
Or are they talking many feet?

The installation I have in mind would put the coax length at ~2.5 - 3 feet. Is that too long? I'm using RG-400.

That should work just fine. The GDL 82 should be inserted into the transmission line as close to the antenna as is feasibly possible.

Thanks,

Justin
 
I have a couple of small puck GPS antennas under the canopy. For example one for the Garmin 496.

The instructions for the GDL-82 seem to indicate that he GPS antenna should not be near the canopy.

So does that preclude putting the GPS antenna under the canopy?

Thanks
 
Good Afternoon,

This will be optional in your installation. The fault lamp is inactive when ADS-B Out messages are providing all FAA required information, and active when the system is not transmitting all FAA required information.

Please let us know if you have any other questions.

Thanks,

Justin

How is this fault lamp supposed to be wired? A 12 volt incandescent light? One side the the GDL-82 and the other to Ground?

Any other wiring requirements? transistors/resistors etc?

Thanks


How much current can the lamp be?
 
GDL 82 Fault Indicator

How is this fault lamp supposed to be wired? A 12 volt incandescent light? One side the the GDL-82 and the other to Ground?

Any other wiring requirements? transistors/resistors etc?

Thanks


How much current can the lamp be?

Working from Revision 6 of the GDL 82 TSO Installation Manual, we specify the lamp to be used on page 3-3, and the wiring information can be found on page 10-2. The GDL 82 provides a ground to activate the lamp, while voltage is sourced externally. Do you have the latest revision on the manual? If not, shoot us an email to [email protected] and we can get a copy sent over for you.

Thanks,

Justin
 
Working from Revision 6 of the GDL 82 TSO Installation Manual, we specify the lamp to be used on page 3-3, and the wiring information can be found on page 10-2. The GDL 82 provides a ground to activate the lamp, while voltage is sourced externally. Do you have the latest revision on the manual? If not, shoot us an email to [email protected] and we can get a copy sent over for you.

Thanks,

Justin

Hello Justin,

Ah no I have revision 5 - the one offered by spruce.

I will send the email to obtain 6.

Many thanks!

Gregg
 
The GDL-82 output supplies a ground when a fault is detected. I wired a red LED in series with a current limiting 330 ohm resistor between the GDL-82 output and ground. (LED cathode toward ground.) No need for an incandescent lamp, which needlessly draws too much current and can burn out.
 
The GDL-82 output supplies a ground when a fault is detected. I wired a red LED in series with a current limiting 330 ohm resistor between the GDL-82 output and ground. (LED cathode toward ground.) No need for an incandescent lamp, which needlessly draws too much current and can burn out.

I was thinking of a setup like that. Is there some way to rig a push to test with an LED?
 
Back
Top