Are these worth anything?
 

A fellow club member has some health issues and no longer flies. I found these in his basement and are these three worth anything to collectors. An Orbit72, a Heathkit, and a homebuilt galloping ghost transmitter

You might try contacting the AMA to see if are is a rare one that they may want for their museum. They look pretty cool.

Sadly, the majority of older transmitters only have value for those trying to add to a collection. Most every club has older members with boxes full of these sorts of transmitters and other equipment. Certainly there are exceptions and some rare transmitters are much in demand.

Yes, they have value. Do some google searches, you might be surprised. I recently sold off a working Ace Pulse Commander and an unknown condition Micro Avionics single stick system. Was very happy with what they sold for. Probably could have gotten more on eBay, but sometimes the quick sale is the best way.

Without receivers they probably aren't worth much. Like someone above said there are plenty of them around. Many people like to use them in antique aircraft but they have to be working and that means a receiver.