chicago_mike wrote:1Khz sine and square waves.
It's a 2 channel scope, but I only have one probe. I think I can Save the signal on either channel on my scope though. you know, to compare, like you say.
HEres my question: Lets say I do have the circuit wired right...for inverting the signal. However, its NOT inverting....
Could the opamp be bad?
It's possible, do you have power going to it?, also, are you using a single, or dual-tracking power supply?, if it''s single then the output of the op-amp should be sitting at 1/2 the supply voltage...
Another thought is that you might not have the + input of the op-amp referenced to circuit-ground, if that's the case then the op-amp wouldn't be amplifying the difference between the + and - inputs, and because the - input is tied directly to the output via a resistor (if it's providing amplification), or via a wire-link (acting as a buffer), then you'll be seeing the signal on the output of the op-amp in phase with the input....
My other thought is that because you've only got one scope-probe, when you touch the tip to the output the scope's triggering puts the trace in phase with the input, you should try and buy a second scope probe as this will enable you to use both channels of your scope to compare the input and output signals, the phase difference between the two signal will then be clearly displayed on the scope...
In the meantime, you could build a differential amp with a spare op-amp IC, feed one signal into the + input and feed the other signal into the - input, the op-amp ic will then amplify the difference between the two signals, if both signals are in-phase and equal in amplitude/level, then the output should be zero, meaning no-difference, if on the otherhand one signal is 180 degrees out-of-phase with the other, and of same amplitude/level, then you should get an output equal to the difference between the two signals....

Genius is not all about 99% perspiration, and 1% inspiration - sometimes the solution is staring you right in the face.-Frequencycentral.