Do all transponder and ADS-B units require external antenna

[Jonathan St. Cloud]

Was wondering if all transponder and ADS-B units require an external antenna to be mounted on the beautiful flowing lines of a glider? Is there a way to have an internal antenna?

[[email protected]]

On Monday, March 16, 2015 at 7:26:04 PM UTC-4, Jonathan St. Cloud wrote:
> Was wondering if all transponder and ADS-B units require an external antenna to be mounted on the beautiful flowing lines of a glider? Is there a way to have an internal antenna?

Well, it depends. Metal gliders have to have external antennas for everything
since they're natural Faraday cages. Fiberglass gliders are transparent to
the microwave frequencies, so they can have internally mounted antennas.
More modern carbon fiber gliders are Faraday cages, but they often have
fiberglass tails to accommodate internal antennas. Still, I've seen
external transponder antennas on modern gliders.

Matt

[[email protected]]

JS are mounting their XPDR antennas in the fin. An elegant, low drag solution. If by ADB-B you're referring to out, your XPDR is going to do that job for you, ie. same antenna. If you're referring to the antenna of a certified GPS source such as a Trig TN70 or Freeflight 1201 then I've only seen external mount antennas. Having said that, I don't believe the manufacturers consider gliders at all as they are the standard, surface mount, 'do not paint' variety you find on metal aircraft. Shame really.

CJ