There are all sorts of interesting items to collect.  Rather than build a huge collection of wireless sets, or valves, or test meters, or whatever; I've decided to simply keep a variety of things because each of them pleases me in some way.   I'm particularly fond of items that have been built by, or used by, past enthusiasts (a.k.a. makers).

 Early digital clock 
 Metal valves 
 Home-made rotary switch 
 Test equipment 
 Wireless World 

Other collections, collectors and the like