Garmin has joined the portable ADS-B parade with their GDL 39. The receiver sits on the glareshield, receives both free weather and ADS-B traffic targets, and displays the data in Garmin’s Pilot App for the iPad or on the aera 796 portable navigator. It’s about the size of a sardine can, which makes it bigger than Sporty’s Stratus, and is almost twice as large with the optional battery attached. That battery will also cost you $100 extra, and the traffic display might not be what you expect.
ADS-B traffic received by the GDL 39 is directly from aircraft sending ADS-B out signals, and from FAA ground stations. However, unless your aircraft has an ADS-B out signal of its own, traffic around your aircraft might not be displayed. The GDL 39 is $799 without the battery, although if you purchase before August 31, Garmin will include it for free. The GDL 39 can connect via Bluetooth with two iOS or Android devices at once, and by cable to aera 700s, aera 500s, 696s and G3X cockpit displays. It will be able to connect via Bluetooth to the 796 with a future update to the 796.