In the vacuum tube era, there was lots of "composite tube" in which two or more elements are composited in single tube. One example is 1U5, diode-pentode.

Of course, "diode" is not semiconductor but its real meaning device. The above pinout image shows diode between #4(plate:anode of diode) and #1 for cathode of diode. As same as semiconductor diode, vacuum tube diodes are application specified (power rectifier or RF rectifier) and the one in 1U5 is for RF rectifier. So utilizing this diode, we can make "pure vacuum tube radio".

Here is the schematic of "diode-pentode" diode. It is also "reflex radio" where the rectified signal has a feedback through R4 and audio signal goes again to resonator.

And this is the whole circuit except for resonator (VC and bar antenna). As you can see no "semiconductor diode". Actual operation can be found in the following movie! Yeah, it's working!