help needed in analyzing this circuit

[agnaatha]

Hi all, I badly need to know what this circuit does and how it works. Please help me by explaining what the fet part, rc part does here.

http://i52.tinypic.com/14njkv7.jpg

 

[davenn]

looks pretty much like a FET, RF amplifier followed by a diode detector and an audio amplifier

have you got any more background on the cct ? where did it come from ?

Dave

 

[agnaatha]

looks pretty much like a FET, RF amplifier followed by a diode detector and an audio amplifier

have you got any more background on the cct ? where did it come from ?

Dave

Its a question from an unknown book. In the question it is regarded as EM survey unit
Here is the full question, dont know from which book it is..

Sorry I should have posted this before.

 

[duke37]

It looks as if the circuit will not work without a DC path for the diode. Add a resistor from the junction of C and the diode to ground. It would also help if there was power to the amplifier!