LW-AM radio receiver with high IF and non resonant loop antenna скачать в хорошем качестве

LW-AM radio receiver with high IF and non resonant loop antenna

It`s an experimental AM radio receiver. I wanted to design a simple radio with minimum LC resonant circuit. It consists from 1) A geterodyne (barrier circuit with Ucb = 0) with stabilization of amplitude (achieved by shunting LC resonsant circuit with CB junction). 2)A switching RF mixer (mosfet BF998) , 3) simple crystal IF filter (two crystals 10.7MHz) 4)An IF amplifier with a dynamic load 5)A sensetive detector from BJT and diode. ONLY ONE resonant LC circuit using in the geterodyne for tuning on a radiostation. Other coils - inductors or wideband transformers (windings - twisted wires with a NiZn ferrite core). Main disadvantage of this radio - is a low intermodulation distortion threshold - because there is a parasitic diode in the RF mosfet mixer.