There was a time when you could do what you wanted in your yard and hams could build giant antenna farms. These days, there are usually laws or deed restrictions that stop that from happening. Even if you can build an antenna, you might want to quickly put up something temporary in an emergency.
[Eric’s] solution? Suspend a wire from a weather balloon filled with helium from the local WalMart. The 8 foot balloon took two containers (18 cubic feet) of gas before it would rise sufficiently. Once you have a floating balloon, the rest of the concept is simple: connect a wire (100 feet of 26 gauge), use a tuner to match the load to the transmitter, and you have instant antenna.
The Army used this same technique with the SCR-578 survival radio. Instead of helium, a chemical reaction produced hydrogen that lifted a balloon that would hoist a kite that kept the antenna aloft.