I have upgraded my response; It follows:
The GDL 82 is Garmin’s low-cost solution to the ADS-B “Out” mandate. But if you don’t already have a WAAS (high integrity) GPS receiver to feed position data to the GDL 82, you will have to upgrade to a unit with a WAAS receiver. If you do have a WAAS receiver, you can buy the GDL 82 for $1799. It will work with your KT76A—provided that your KT-76A is married to an encoder—or with any existing Mode A or Mode C transponder.
The installation consists of installing the GDL “box”, that measures 3.3 inches by 1.5 by 9.2 inches at a convenient place upstream of the transponder antenna in the coaxial cable between your transponder and the transponder antenna. That part is very easy.
The second part requires the installation of a GPS antenna. Since GPS antennas must be mounted on an upper surface of the airframe, you’ll need to mount the antenna—as near the centerline of the aircraft as possible—and remove enough interior to route a coaxial cable from the antenna to the “box.”
The GDL 82 will not work with Mode S transponders. There’s not much more to it. The avionics installer will need to input some confirmation information, and you’ll need to fly a confirmation flight but that’s easy.
The GDL 82 transmits on the 978 MHz and is called a Universal Access Transceiver (UAT). Installation fulfills the 2020 mandate for ADS-B Out.
ADS-B “In” information includes NEXRAD weather, traffic, METARS, TAFs, NOTAMS, TFRs and other very helpful information in your cockpit.
There are different ways to display the “In” information. One commonly used method is to send the “In” data via Bluetooth or Wi-Fi to an Electronic Flight Bag (EFB) app on an iPad or other brand tablet. There are a bunch of very good EFBs out there such as the Garmin Pilot, the Appareo Foreflight, the Seattle Avionics Fly Q and others. Receivers can be battery-powered portable units such as the Garmin GDL 39, the Appareo Stratus 2, and others. I use a Stratux ADS-B Dual frequency unit.
The main drawback of the portable units is the somewhat short battery life. Most units will work for between 4 and 5 hours on a charge. The Statux I have needs a portable battery to power it. I have 2 EasyAcc slim line battery packs that provide enough power for 8 hours of use.
Many portable units can be powered from a USB power output plug in the panel. I installed one in the same hole the cigar light was in. I got the one from Guardian Avionics; other suppliers include Mid-Continent Instruments and Appareo Stratus.
If you do not have a WAAS high integrity GPS to tie to the GDL 82, other options include installing a new transponder with a built in WAAS GPS and ADS-B “Out” capabilities such as the Appareo ESG and the Garmin GTX 335. These retail without installation for $2995.
There is a great deal of information about ADS-B at Garmin’s ADS-B Academy (https://www.garmin.com/us/intheair/ads-b) and in the avionics section of the Pilot Shop the Sportys website (www.sportys.com).
Happy Flying
