Consider the simple AM detector below:
Inductor L1 and capacitor C1 builds the "tank circuit", which purpose is to filter all frequencies, except the selecteded one. However, I'm having trouble to fully understand this circuit.
In my understanding, the circuit above would not work, because the antenna is shorted with the diode D1. The diode is receiving the same voltage as the antenna, so the tank circuit is, theoretically, not interfering in the output.
If I was trying to build a tank circuit to select a specific frequency, I would do something like this:
With this configuration, the resistor acts like a "voltage divider", and the frequency plot would be similiar to this:
(To select frequencies near 600kHz)
Of course, if I try to simulate the same circuit, but without the resitor, Vout becomes the same as Vin, since there would be a short between them. But this is exactly the case in the AM detector! How it works, then?
Any help is appreciated, Thanks!
Obs.: The AM detector I showed is used in almost every AM received schematic I found.