The building has lots of drab army green antennas outside and some military looking missiles. Entry is free, although I am sure they take donations.
Inside is both a hands on museum that explains the history of electronics and a well stocked library on the same subject.
The museum starts with the basics (what is an atom, what is an electron - what is lighting - how does it work). Then progresses you on through experiments with electricity and what exactly is the difference between ac and dc currents. You then move on to how electrity is delivered to your home through various devices and finally, a magnetron (used in your common microwave oven - which they have a 1952 circa model in the museum - very cool).
After that, you move on to communication uses of electricity and progress from the first short wave transmissions to morse code to telephone and telex machines - all the way to faxes and modern day computers. In addition, there is information and exhibits on the very first commercial broadcast in America.
The next section is dedicated to radar and you learn about how it was discovered and how they kept improving it and what uses it gets put to (this is where the military stuff comes in). From there on, it is straight military stuff, but it is extremely interesting.
The museum is well laid out (as only an engineer could) It is logical and there are plenty of hands on exhibits that help you learn some rather difficult concepts. (I now get the difference between ac/dc - however, I am still a bit fuzzy on lightning).
And... if you have an interest in the subject and will be staying in the area, you can check out books and video's from their library - but most of this material is pretty technical - so you would really have to be interested.