Newby how-to audio signal injection

[ncblt]

I finally got my o-scope and have been having a great time with it. I have a freq counter and other misc equipment.
I am know looking at doing full alignments and know there is a way to do audio signal injection from my pc to radios. My question is, when I see "Audio signal 30 mV, 1 KHz to microphone" , how do I accomplish this ? Feed the sound card to the mic input ? I am concerned about overloading the circuit. 30mv is my concern.
Thanks for helping a new guy trying to step up.

 

[sp5it]

You can adjust output level via windows audio mixer and measure output level with your scope before connecting to mic input.
Mike

 

[W5LZ]

... And in case your soundcard produces more than 30 mv of output at minimum, an attenuation circuit can be used. What's the output from a soundcard? I have no idea, measure it.
- 'Doc