I build the Bitx20 V3 Audio Section in about 3 hours.So it was time for the next chapter,the BFO/Modulation section.I took another 5 by 5cm double sided board.On the picture bellow you see the transformer made of a binocular core.Put 13 trifilaire windings thru the core and beep the wires for right connection.Stick it to the PCB with a hot glue gun.In this stage ,I put it together with the audio section.Apply 12Vdc to the receive line and now you can receive the "beeps" on 10MHz when you use a 10MHz crystal as IF.This is also the part where you can determine if your crystals for the filter match.I used a IC-connector,so I can easily change the crystals in and out the socket for measuring the right frequency.So you can pair the crystals for the crystal filter.Just connect your frequency counter and search for 5 chrystals where the frequency`s are closed together.
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