Quick Question About Function Generator Use

[mart1n]

I'm experimenting with RC low pass and high pass filters and had a quick question.

Is it OK to combine the two channels from my function generator into one test circuit?

For instance if I have a low pass filter, could I input one FG channel with a high frequency signal and a 2nd FG channel with a low frequency signal?
I know that might seem like a dumb question, but I just wanted to make sure it was safe, wouldn't damage the FG, etc.

Would I need a BNC T adapter? Or can I just add both channels to different parts of the power/ground rails on my breadboard?

Thanks!

[David Hess]

Both inputs can be used to drive the same circuit without limitations if they see the termination they are expecting.

If both channels are connected directly together, then the peak current each channel will see can be doubled as with a bridged amplifier which a good design should handle without problems but who knows?  Doing this also presents an impedance mismatch depending on the exact configuration which will be a problem at high frequencies.  A resistive divider/combiner solves this problem and presents the proper impedance at all ports but introduces 6dB of loss which may be unacceptable.  Over a limited frequency range, an RF splitter/combiner could be used instead to avoid the power loss.

If both signals need to be combined without limitations, then a small summing amplifier could be used.