Electronic – How to Amplitude Modulate this


I recently built this circuit, and could hear a nice full quieting signal on my short-wave radio with a 7.2 megahertz crystal for the 40 meter band.

What is the simplest way I could Amplitude Modulate this signal with a microphone or computer output port so my Short wave radio could hear this signal and I could potentially make some HAM contacts?

And by the way I do have a license. It is KDØWHB and I have general privileges.

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Best Answer

What you have here is a straightforward minimal component crystal oscillator.

Your best bet is going to be to follow it up with an amplitude-modulated amplifier stage, along with the necessary microphone amplifier and signal conditioning.

Best resource will be OLD copies of the ARRL Handbook. Hit your libraries.

If you can find a copy of DeMaw & Hayward's "Solid State Design for the Radio Amateur", it will give you a lot of help, although not much on AM. Copies OCCASIONALLY show up on Amazon for reasonable prices.

--de John WB5YOO (Amateur Extra)