On Saturday, January 26, 2019 at 12:51:52 AM UTC-5, Don Grillo wrote:
Greg, your mode S transponder will display your N number, your altitude, and your squawk on ATC radar, it will display your position and how high or low you are on TCAS equipped aircraft (ex. 2000 above or below) and it will display your position and altitude on ADS-B in equipped aircraft.

If you have flarm, you should be able to see ADS-B out equipped aircraft on your flarm display with a limited range of 5-6 miles. (Oudie, flarmview etc)

A Mode-S equipped glider without ADS-B OUT will only show up on ADS-B IN equipped aircraft if the glider is within ATC radar coverage AND if the other aircraft is ADS-B OUT equipped AND is within range on an ADS-B ground station.

If you are flying at relatively low altitudes in remote areas, neither of these conditions may be met. Equipping the glider with ADS-B OUT makes you visible to all dual frequency ADS-B IN equipped aircraft in your vicinity.

Remember that PowerFlarm equipped gliders will not see ADS-B OUT UAT equipped aircraft, so you are only seeing a subset of the traffic out there.