Garyl
Full Member level 5
I still don't have the output stage (transistor, mic, etc) soldered, but I will remember that. Could I just connect MP3 player output instead of mic and then try to transmit signal few meters across the room?So when it is all working, you make sure no audio enters the mic input then adjust the two potentiometers for minimum (ideally zero) output.
I've added 15pF capacitor and it's working all the time now.The oscillator should run no matter where the control is set, if it is stopping it is probably at the extreme of minimum value. You could try adding a small capacitor across it to prevent the value reaching so low (~5pF) or you could try changing the transistor for one with higher gain.
When you hear a station near 3.58MHz, adjust the 'can' transformer for maximum signal. It is the equivalent of the bandpass filter on your Lidia receiver but because the tuning range is so narrow on this one, a peaking filter is more appropriate to use.
Okay, first I wanted to try testing this receiver with test signal generator, but then I realized I am already picking something with my crude "cable from roof" antenna.
Here's what I managed to receive during this evening:
View attachment 2017_09_08_20_34_46_VK3AJG_is_this_CW.zip
View attachment 2017_09_08_20_38_23_VK3AJG_is_this_CW.zip
View attachment 2017_09_08_21_13_13_VK3AJG_is_this_CW.zip
I'm not sure if it's CW or maybe that RTTY...
... still, it's good that I have received something, because my crude "cable from roof" antenna here is so bad that even my Lidia receiver fails to receive anything understandable...