Many types of antique radio that has been produced, such as:
Morse only sets
The first radio receivers used a coherer and sounding board, and were only able to receive morse code, and thump it out on the board
Early home made sets
The idea of radio as entertainment took off in 1920, and radio ownership steadily gained in popularity as the years passed. Radio sets from before 1920 are rarities.
These basic radios used no battery, had no amplification and could only operate headphones. They would only receive very strong signals from a local station. They were popular among the less wealthy due to their low build cost and zero run cos
TRF sets (Tuned Radio Frequency) are the most popular class of early radio. These used one or more valves (tubes) to provide amplification. Early TRF sets only operated headphones, but by the 1930s it was more common to use additional amplification to power a loudspeaker, despite the expense.
In this era of early radio, only the wealthy could afford to build a superhet. Such sets required many valves and numerous components, and building one was a sizeable project.
World War 2 created widespread urgent need for radio communication, and foxhole sets were built by people without access to traditional radio parts. A foxhole radio is an illegally constructed set from whatever parts one could make, which were very few indeed. Such a set typically used lighting flex for an aerial, a razor blade for a detector, and a tin can, magnet and some wire for an earpiece. I.e. they were crude crystal sets.
to be continued...