Check Handi-hams. I think they still have a tuning aid which is similar to
the Conway Tuning Aid which is a VCO you hook across your meter. If your
rig has a built-in meter with SWR, you can hook it there and get readings on
your drive level, etc. If you have an amp, you'd probably want to install a
quarter-inch stereo jack across that meter so you can hook the tuning aid up
to it.
Steve
K8sp