Radio Circuit Analysis

[f4cepl4nt]

How would I go about analyzing a circuit such as the one below? I have a few questions to start with:

1) Do you consider the antenna an AC voltage source?
2) What is the purpose of C2? I'm assuming it's to reduce noise, but how exactly does it accomplish this?
3) If I wanted to use an NPN transistor instead of a PNP, would I just have to switch the diode and battery orientations? Along with capacitors if they are polar.
4) What is the ground symbol at the bottom of L1 connected to? Is it like the other half of the hertz antenna, or just connected to some big piece of metal, or what?

One note: The capacitor on the schematic is a variable cap with a rating of 365 MMF, whatever that means. If someone could fill me in on what that means that would be cool too, because I got the schematic from a very old book

[mugsby]

output to what? it looks like a one stage receiver.

[audioguru]

It isn't a receiver. It is a tuned circuit followed by an AM detector that doesn't have a proper DC load nor filter, then an improperly biased transistor as an audio amplifier.

It is similar to an old fashioned crystal "radio".

The tuning capacitor for many AM radios is 365pF when turned to its max. "pF" (pico-farad) is micro-micro farad which some people used to write as 365MMF.