it's old but will it do the job? considering that it's free?

click here

While I love tubes in audio, the one place they really don't have a use anymore is in test equipment, whether that's o-scopes, VTVM's, grid-dip meters, whatever.

Pain in the ass to keep calibrated as the tubes age, and probably uses some odd sweep tubes that'll be very hard to replace. Just get a solid-state Tektronix and be done with it.

that thing is sweeeeet though.

I've got a Velleman HPS10SE which I use just for audio test purposes...served me nicely untill now. The display isn't spot on accurate but it does it's job.