I have a remote hampton bay ceiling fan, it has no chains and I do not have the remote, can I use a universal remote?

You can try just the transmitter but the frequency must be the same and the DIP switch settings must match also. You might have to replace both the transmitter and receiver and make sure the DIP switches are set the same.

I agree, just get both the transmitter and receiver all in one package. The chances you could get a new transmitter to work on an old OEM recievr is quite small and not worth the time