Amplification in a commerical radio (Rx)

[Resistanceisfutile]

I was just wondering, does a commercial radio (ya'know, one you use to listen to radio stations on) amplifying before or after demodulating the signal?
If it does amplify the RF signal before demodulating it (if I was to remove/modify the tuned circuit if this occurs before amplification), could I use it to amplify a radio signal generated by a modulating circuit? (Assuming that the amplifier circuit, and my transmitter used the same type of modulation).
Example:
Modulating circuit --> Amplification circuit taken from Rx --> Tx Aerial

 

[chuckey]

Virtually all receivers are of the "superhetrodyne" type. The incoming RF is taken via a tuned circuit to a mixer. Another input to the mixer is a local oscillator, this is tuned to the incoming frequency plus a preset frequency (the intermediate frequency). One output from the mixer is at IF frequencies and it will contain all the modulation information that was on the original RF signal. This IF frequency is then amplified and demodulated to provide the wanted audio/video output. Some specialized receivers have an RF amp as do VHF/UHF TV tuners.
Frank

 

[D.A.(Tony)Stewart]

Considering that an FM signal might be only 1 to 100uV in a spectrum of other signals and noise that could be 30 to 100dB stronger.

First you need a bandpass/band-reject filter then amplifier with 2nd stage filtering well before the demodulator to get the Carrier to Noise ratio (CNR) well above 10dB so that the output SNR can be improved to > 50dB due to the IF Filter, FM improvement factor and pre-emphasis.

Since this is low power and is restricted to 85~105MHz band, it has little benefit to a transmitter path.

 

[Audioguru]

A radio receiver uses a voltage amplifier. A radio transmitter uses a power amplifier. They are different.

A simple radio transmitter is very simple, look in Google Images. An FM transmitter can be made with one transistor, one LC tuned circuit and a few resistors and capacitors.