[TA Forbes]

For reception this is not critical for the kind of radiography most of us require. With the variety of stations/frequencies we listen to (KHz/MHz) a simple longwire is sufficient.

In the military they use a matching unit that electrically "matches" the fixed length antenna included with the set to the frequency that is being broadcast/recieved.

I have a couple of "inverted L" antennas here. These are pretty good if you have an antenna inside your home. Also have a pretty long one that goes up one side of a large series of 3 windows, across the tops, and back down the opposite side. It is my best antenna. Go figure.....

In my former life the antenna configuration was critical in term of length, orientation, and take off angle. But in these cases we were given a set of frequencies to use and it was easier to prepare your system before you went out in the "bush."