I put your circuit into LT Spice (a simulator) and it oscillates nicely at 100 kHz. So, perhaps your results are due to stray capacitance (as already hinted by previous responders), or perhaps you didn't build it exactly per the schematic. Perhaps you could post a picture of the breadboard. Meanwhile, here are some things to check:
- are the 2n3904 transistors connected correctly; i.e. Collector, Base, and Emitter in the right place?
- is the supply 5 Vdc?
- all the grounds connected as shown?
- is the base of Q1 at a DC level of 2.5V (ignore the small transient for now)?
Jake
I kind of suspected that the breadboard could be part of the problem. I double-checked everything and it all seems right. I am not real proficient with LtSpice, but I might try to put this in there and see what I should be looking at. After all, this whole exercise is about me learning.
- I double-checked all of my connections, and verified the supply voltage.
- I double-checked all grounds, and they are tied together correctly.
- The base of Q1 is right at 2.5V.
Tie the left transistor's base to ground with a capacitor.
And BAMN! I placed a random capacitor between Q1 base and ground. The signal looked so much better. I then tried a smaller value capacitor (.001uF) and have some oscillation at around 160kHz or so. I have been messing around with resistor values, so I need to go back and make sure that I am using the correct values.
Thank you both for your help and suggestions. I'll see if I can work this out.