Abstract: A portable antenna support structure which can be carried by a vehicle and includes an inflatable balloon and telescopic extension poles that are pivoted to the sides of the vehicle at the front and back and may be extended radially when the vehicle is at rest. The vehicle carries a storage tank of compressed helium which can be transferred to the balloon for inflating it, the balloon being equipped with an antenna. Guy lines extend from a winch on the vehicle and are passed around pulleys arranged at the outer ends of the fully extended telescopic poles and then are secured to the balloon for holding it and the antenna in a fixed position and at a desired height above the vehicle. The balloon may be pulled down to the vehicle by the winch where the helium may be withdrawn from the balloon for collapsing it and the gas may be compressed in the storage tank until its next use.