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Garmin GDL 82 available?

One thing to be aware of before going the GDL 82 route is you may need a new transponder antenna. Install manual, page 4-4 lists the antennas that apparently perform well enough at the 3 frequencies, 978, 1030, and 1090. These are not the everyday mode C antennas that are tuned for the 1030 and 1090 and are likely already on your bird.

Stan,
just as an FYI, the list in the manual is just a reference for recommended antenna's that we have tested in the event that one might need to be replaced. the GDL 82 is designed and intended for use with current airframe systems in most cases and if you have a good, in working order transponder L band antenna, it will do just fine with no need for a replacement.
 
L-band Antennae

if you have a good, in working order transponder L band antenna, it will do just fine with no need for a replacement.

That sounds like a common sense approach. The manual (section 4.4) arguably eliminates a common sense approach saying....

"The GDL 82 requires the existing L-Band Ultra-High Frequency (UHF) antenna(s) meet the following specifications:  Standard 50 ohm vertically polarized antenna with a VSWR < 1.7:1 at 978 MHz and < 1.5:1 at 1090 MHz..."

I have a common transponder antenna, a CI-101 and VSWR at 978 is not listed. The Ted monopole for ADS-B doesn't publish for 1090. IMO, if one is a stickler, there is going to be some more work to measure the VSWR, or dollars spent on an already tested antenna.

My test flight went fine. Because I have an antenna intended for 1030 and 1090, I will be curious to see how good 978 out is, compared to other UAT installs.
 
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Figure 5.1 in the install manual wrong

Figure 5.1 shows connector J821 and the middle row of pins shifted incorrectly to the right. It doesn't matter how many times the connector is turned over, still can't make it look like Figure 5.1! (Pin 10 is proud when 6 should be) So the figure was ignored and the connector was wired per TABLE 5.1 and everything works as expected. Those with young eyes, this may be academic, but for those with presbyopia, we go through life looking at shapes and arrangements, paying less attention to those darn little numbers!:D

**Garmin Support replies Rev. 4 of the install manual will have the correction.
 
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I noticed that too. The colors in the USB cable are reversed from the common
definitions but it works the way shown in the install manual. Having a bit of a
struggle with VHF interference. Everything else was really slick!! BH
 
I noticed that too. The colors in the USB cable are reversed from the common
definitions but it works the way shown in the install manual. Having a bit of a
struggle with VHF interference. Everything else was really slick!! BH

The VHF interference could be coming from your ELT. Is your COM antenna close to your ELT antenna? Do you have an older 121.5 ELT? If so try disconnecting the ELT antenna from the ELT and try the COM tests again. If the symptoms go away you'll need a notch filter or to update your ELT to the new GPS version.

This is a known issue.
 
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Yes, ELTs are usually a disaster. It might be in this case. Haven't tried putting one of those GPS harmonic traps on the ELT--ought to work. Thanks BH
 
GDL82

Figure 5.1 shows connector J821 and the middle row of pins shifted incorrectly to the right. It doesn't matter how many times the connector is turned over, still can't make it look like Figure 5.1! (Pin 10 is proud when 6 should be) So the figure was ignored and the connector was wired per TABLE 5.1 and everything works as expected. Those with young eyes, this may be academic, but for those with presbyopia, we go through life looking at shapes and arrangements, paying less attention to those darn little numbers!:D

**Garmin Support replies Rev. 4 of the install manual will have the correction.

You are correct,the picture is incorrect and the middle row is shifted to the right and should be to the left,the pin numbers are on all the pieces though just to verify when you push the pins in.
Funny how they didn't catch this.
Everything else is correct though.
 
1090 Version

For those of us that fly outside the US in our aircraft, we need the 1090 version w same price point access.
 
GDL 82 Does not work

Installed the GDL 82 a couple of days ago. Very simple to install, but it does not send out ADS-B to ATC. Checked the configuration several times and by all indicators on the computer, it is working, ATC does not receive any ADSB data. I think Garmin hasn't worked the bugs out of this device yet. In retrospect, I would have bought some other unit. This is an expensive experiment. Anyone having this kind of experience with their installation?
 
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Installed the GDL 82 a couple of days ago. Very simple to install, but it does not send out ADS-B to ATC. Checked the configuration several times and by all indicators on the computer, it is working, ATC does not receive any ADSB data. I think Garmin hasn't worked the bugs out of this device yet. In retrospect, I would have bought some other unit. This is an expensive experiment. Anyone having this kind of experience with their installation?

I’m not sure how to interpret your note.

I installed a GDL82 about a month ago. Although I have talked, on freq, to HOU Appch and GLS tower, they don’t see my ADS-B out.

However, when I use the ADS-B performance test website

https://adsbperformance.faa.gov/PAPRRequest.aspx

it reports that my GDL82 is working fine. Not a single error. So I trust that my GDL82 is working fine, meets the 2020 requirement etc....

It has been discussed on other VAF threads that, at least in some areas, ATC doesn’t seem to have the equipment and/or training to “see” the ADS-B out data.

Another way to test it would be to operate ForeFlight with an ADS-B receiver like Scout or a GDL39 and see if the ADS-B data appears. If you test that in your own plane, you may only see your data for a second or two, then ForeFlight figures out that it is your own plane, and stops displaying your own data on top of your plane. Then you can look in ForeFlight, More, Devices, and drill into the Ownship data to see what your GDL82 is transmitting.

Carl
..
 
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GDL 82 Does not work (follow up)

Thanks for your reply. I ran the FAA evaluation of my test flight, and it passed with 0 failures. It seems the Seattle Center could not see my ADSB data either during my flight test, but my unit is working properly.

Thanks a bunch for the advice. This forum is priceless.
 
Thanks for your reply. I ran the FAA evaluation of my test flight, and it passed with 0 failures. It seems the Seattle Center could not see my ADSB data either during my flight test, but my unit is working properly.

Thanks a bunch for the advice. This forum is priceless.

Concur All! Absolutely priceless! Happy I could assist, and in my time on VAF I?ve received much more than I could ever contribute!

Carl
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GDL-82 WIRING HARNESS

Hello All

I was wondering if anyone here bought the wiring harness offered by AC Spruce (or anyone else )for the GDL-82??

At $75.00 CDN (About $50 USD ) I wonder if it is worth the money vs the time to build one myself??

Thanks

Bruno
 
Power and Discretes Cable, build or buy?

Spent over $50 US to get help and buy specialized crimp tool inserts for hi-density pins. I didn’t mind the expense and time (retiree) required to build up the GDL 82 cable since I enjoy working with wires.

If you want to economize and don’t already have the proper crimp tools I’d guess buying the pre-built cable is the best option.

Your Mileage May Vary!

Carl
..
 
Hello All

I was wondering if anyone here bought the wiring harness offered by AC Spruce (or anyone else )for the GDL-82??

At $75.00 CDN (About $50 USD ) I wonder if it is worth the money vs the time to build one myself??

Thanks

Bruno
Personal opinion, so take it for what you paid for it.

$50 is a steep price to pay to have someone else do something you can do yourself. Of course only you can determine if you can undertake this task and if so, is it worth that to pay someone else to do it for you. However, let me say that it is not a difficult task. Now granted, there is the issue of having the right tools. If you have no intention of crimping wires again in the future then maybe you will have to decide if the price is appropriate compared to what it would take for you to buy the tools and do it yourself. There are basically just a handful of wires you have to install, power, ground, LED lead wire (if used), anonymous switch (if used). That's it for the pinned DSUB connector! There is the coaxial antenna cable for the ADS-B antenna that also would have to be crimped if you built it yourself. None of that is complicated but it does take the tools. If you do not have them, maybe someone you know has them and you can borrow them.

As a builder one acquires quite a collection of tools to do each task. It is one of those things where a person can never have enough tools. I bought my tools whenever I had to perform a new task. I would never really consider selling them even though I am not building at this time. I believe tool purchases really are an investment. There will always come a day when one will need them for the next project down the line.

Ok, my .02.

Live Long and Prosper!
 
Wiring Harness

Bruno,

I've bought pre-built harness from Stein (Tru-Trak), Spurce (GRT200), and the local avionics shop (transponer & encoder). All have been top quality. But when I installed my Free Flight Rangr Lite, I built it and it was my first one. Bought the wire and pins from Stein and borrowed the crimpers for the pins and coax. It was fun and I learned a few things. For something more complicated, would likely go with pre-built.

Jim Berry
 
Carl,Steve & Jim

Thanks for the reply.

I already have the tools and wiring so it is a none issue there but I thought there were more wires involved (I didn't have a chance to look at the manual yet ) ..and thought I might save a lot of time

I've done all the wiring on my Skyview installation so it shoudn't be too much trouble doing this one..

Thanks again for your feedbacks.

Cheers

Bruno
 
Faulting fault light

While still searching for satellites the Software Tool indicates a Fault. The tool actually displays a Fault count, another fault can be that the transponder is either off or in standby mode. Interesting that these Faults do not turn on the Failure Annuciator light. Therefore it does not appear that the pilot has any information that the Internal GPS has captured enough satellite signals to have a valid position.

The Failure Annunciator light is turned on momentarily during power up. At least the multimeter chirped to indicate a momentary continuity to aircraft ground.
..

My annunciation light is now hooked up and I?m seeing the same thing. It turns on long enough at startup to confirm the light works, then shuts off, before a valid position is acquired. Also, later when switching the transponder to mode A, that shorts the GDL the pressure altitude and should cause the light to turn on. It doesn?t. I trust we can get a software update, if not a useful one, at least one that will turn it on for a few seconds randomly for the entertainment of passengers. :D
 
My annunciation light is now hooked up and I?m seeing the same thing. It turns on long enough at startup to confirm the light works, then shuts off, before a valid position is acquired. Also, later when switching the transponder to mode A, that shorts the GDL the pressure altitude and should cause the light to turn on. It doesn?t. I trust we can get a software update, if not a useful one, at least one that will turn it on for a few seconds randomly for the entertainment of passengers. :D

Hello Stan,

Whenever it makes sense, we like to suppress fault indications for things that are temporary and expected at every power-up.

At each power-up the GDL 82 inhibits the GPS data available fault for 2.5 minutes to allow the GPS time to acquire first fix. It the GPS still doesn't have a usable fix after 2.5 minutes, the fault indication is provided. If the GPS data becomes unavailable in flight, the fault indication comes on immediately.

Pilots typically only ever disable altitude reporting when requested by ATC with the pilot in the loop, so the decision was made to not show a fault indication for this rare and intentional action.

Thanks,
Steve
 
fault light

Thanks for the explanation Steve. I was chuckling- give the coders smart "black tape" to cover the annoyance! I get it. The visual load on the pilot is sometimes high. Why not suppress the light when it is unimportant. Light on or light off, I don't have a strong preference for either behavior, but I do have a preference for accurate manuals so I know what to expect.

On the other, the pressure altitude, IMO, if ATC asks me to shut of mode C, I'd rather see the light come on. Those of us opting for UAT will likely spend a good deal of time, 1200 anonymous. I'd prefer to have the light if my out has a problem. Consider that this UAT unit is targeted toward those who largely want to keep their existing transponder and blind encoder. We are talking old equipment in many cases. Blind encoders do fail and I've seen poor connections as well. Given the structure of Gillham code, when there is an error, it can translate to a wrong altitude that is off a great deal more likely than off a few hundred feet. As long as the team is building smart fault lights.... any thought to a compare statement between pressure altitude and GPS altitude? It would need to have lots of fudge, extreme example, IIRC about 4,500 feet pressure altitude at sea level during record low pressures (hurricane). GPS and pressure altitude seldom agree, but with all the smarts at Garmin.....

In the big picture, probably not a big deal to ignore pressure altitude faults. Most users will probably have some kind of portable IN (that is how I saw the behavior that was contrary to the manual). So if the fault light doesn't come on, perhaps it will be noticed in the "own ship" values. But also big picture, why add a fault light if you don't allow the code to trigger it per the manual- anytime the GDL is not broadcasting FAA required information?

Bottom line for me, whatever Garmin does with the fault code, put it in the manual so we know what to expect.
 
... I've seen poor connections as well. Given the structure of Gillham code, when there is an error, it can translate to a wrong altitude that is off a great deal more likely than off a few hundred feet.
I had that happen recently. The altitude being sent was off by 2,000' IIRC. Turned out to be a loose connection to the encoder.

Interesting trivia regarding the anonymous mode and FlightAware: If you set the switch to "anonymous" before startup, and begin your flight with a code - departing a Class C for example - when you change to 1200 mid-flight, Flight Aware still knows your tail number and displays your entire flight. I haven't tried it the other way around yet. When your entire flight is flown squawking 1200, FlightAware doesn't track you.
 
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