AM Band Morse Transmitter Revisited

The Jaycar Short Circuits transmitter was blogged on here previously:

https://wb9kzy.blogspot.com/2025/12/jaycar-am-morse-code-transmitter.html

I mentioned the damped sine wave output and after a little looking I finally figured out why the circuit acted that way.  The ferrite rod used was from an AM/FM tuner by Oak, bought at Olson Electronics last century.  The connections I made to the smaller winding (L2) were intermittent and were apparently shorted in the circuit  So I tried replacing the ferrite rod with the coil from an old GE radio.  There is no secondary winding (in effect L2 is replaced by a short) so there is no feedback to sustain oscillation, the output waveforms:

the flip flop output is in yellow

When the flip flop connection to the base of Q3 goes low, the coil energy is dissipated in the tank circuit resulting in the damped sine wave.

the signal (blue trace) is a damped sine wave with a frequency of about 1.3 MHz 

And I purposely excluded the term: CW, because the wave is obviously NOT continuous.  An accidental discovery found via a bad connection, sorta like spark, kinda fun :)

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm