Can harmonic happen at 1/2f?

[c_mitra]

It shows 0.731uH. More than 2 times the calculated value.

Please put your inductor standing up; the PCB pads down below are overloading the inductor. If possible, raise it 2-3 mm off the board. Hopefully your problem will disappear.

 

[Audioguru]

My FM transmitter has its coils spaced above the circuit board.

 

[biff44]

True.... but from a single common base oscillator stage with no other tuned circuits around it ???

Brian.

Oh yeah! Trust me on this one.

The weirdest one I ever saw was a non harmonic spur caused by an RF signal bouncing off of an amplifier input, and generating the spur. Took a while to find that one.