In the previous article we discussed using the astable multivibrator as a duel output timer. By just adjusting a resistor and capacitor, you can set the timing to whatever you want. I want to explore that option further and show how this is done, the effect you can expect, and how you can also adjust the duty cycle.
Frequency Adjustment Video
Schematics
The schematics are the same as the previous article but here they are again for convenience.
Video Version:

CAD Version:

Parts List
9V Battery Connector | https://amzn.to/2QycVfJ
9V Battery | https://amzn.to/2rCXfJp
Breadboard | https://amzn.to/2Bkrt8k
Jumper Wire Kit | https://amzn.to/2LiAWRZ
LED Kit | https://amzn.to/2S4lpYy
1kΩ, 100kΩ, & 220kΩ Resistors | https://amzn.to/2rz1mpM
10µF, 0.1µF, & 270µF Capacitors | https://amzn.to/2Rp4zXe
Rigol DS1052E Oscope | https://amzn.to/2QYhmAP