2.
Bandpass filter
: BPF should pass the signal in range 3.5-3.8 MHZ. Make sure that ferrite cores in
the middle position (just 2-3 turns). The fine adjustment of bandpass would be done after next step
3.
3.
RF Amplifier
– put the frequency in the middle of the band (For example, 3.6 MHz). Adjust C18*
trimmer to get maximum of noise of air.
4.
Make the fine tuning of bandpass filters – it should also have maximum noise on the band.
5.
As RF amplifier and Bandpass are ok – it is time to connect the Receiver to antenna (or generator)
to test the working path of Receiver. Tune the Receiver and find the strong signal from station. The
voice could be inaudible.
6.
BFO:
Adjust the C40 to get the right shifting of the quartz filter. It allows to listen to stations and
understand the voice.
