Sorry for the bad title.

Ever notice how a lot of Lex's inventions can lock on to superheroes, even when they're in their civilian identities, without ever telling him where they are?

1. Superfriends episode "Wanted: the Superfriends": Lex invented a "Dream Machine" that could seek out the minds of all the Superfriends while they were sleeping and make them commit crimes to frame them. All without telling the Legion where they were. At one point he actually says "now it will seek out the minds of Batman and Robin, wherever they are!" Really, Lex? It shot out a giant glowing beam to brainwash them, you couldn't have Sinestro follow it or something?
2. The Joker #7 - Luthor- You're Driving Me Sane: Luthor had a machine that could transfer anyone's main personality trait to him. (And SNAP goes my suspension of disbelief) He planned to use it to steal Green Lantern's willpower, but Joker surprised him at the worst time and he ended up swapping his intelligence with Joker's madness. At the very least, for this one to work Lex had to be in Coast City.
3. Batman TBATB: Triumvirate of Terror: When Luthor, Joker, and Cheetah decided to switch arch-enemies, it was easy for the other two to find the Fortress of Solitude and Themyscira. Lex, however, had to find his own way to track down Batman. We really don't get much explanation. He just materializes in the Batcave and says that the teleporters worked perfectly. I mean, did he put a receiver on the Batwing? And how come the Hall of Doom couldn't tell where it was sending him to or pulling him back from?

I'm sure there are plenty more examples I haven't even thought of. Yes, I know, it's all from the Silver Age when nothing made sense, but I still need an explanation! If Lex is so smart, why does he keep designing machines that don't reveal any of his enemies' secrets!?

Because that would be bad for the plot if their identities were revealed.