Yes two straight metal tubes will work until you know what you want on your finale design. You don't want to ask me if the theremin transmits a signal, put an AM radio next to it. If your frequency is too low for AM then tune the radio to twice the theremin frequency. In some countries theremins would be illegal.
I use dangling alligator clip leads when experimenting. Just keep your setup clear of metal surroundings and table top frames.
luc234=> Where on planet earth are you located?
Thanks for the replies. I'm located in central oklahoma.
Another seemingly unrelated question, any idea why the difference from the fixed and the varying frequency is used? Why would it not just create a frequency with the oscillator from the antenna so it falls within an audible range and have that amplified?