You can build a tuner for VHF/UHF, but you really don't want to use one in the shack.
The reason is due to cable losses. To minimize cable losses and get maximum power
to your antenna, you have to keep the SWR on the cable low. If you need a tuner
in the shack, that is because the SWR on the coax is too high. In that case it
is better to adjust the ANTENNA to get a good match (so that the whole length of
cable operates at a low SWR) than to match it in the shack (so only the short
piece between the rig and the tuner has a low SWR.)
On HF the losses in a reasonable length of coax at, say 5 : 1 SWR aren't much to
worry about. Let's assume you are using 100' of RG-213: using VK1OD's handy
transmission line loss calculator (here
) we can see that
the cable loss when matched at the antenna is 0.7 dB, and with the added SWR it only
increases to 1.5 dB, so 70% of your power reaches the antenna.
Repeating the exercise on 2m, the base loss in the coax is 2.5dB and the high SWR adds
a further 2dB of loss, and drops your radiated power from 55% to only 36% of the transmitter
output. You can avoid that loss by matching the impedance at the antenna rather than in
the shack (and by using better coax cable). That's why serious VHF operators don't use
a tuner in the shack.
There may be occasions when one comes in handy - for example, matching 300 ohm twinlead,
but it is better to build a dedicated circuit to do that.
Generally you don't NEED a tuner, even on HF, as long as your antennas have low SWR. Many
antennas can be used on multiple bands without one, but they do come in handy when you
are using an antenna that isn't well matched - often trying to press a single wire into service
on multiple bands. The same applies on VHF / UHF, but you are rarely trying to match a wire
antenna on multiple bands, and the losses due to high SWR usually dictate that the matching
be accomplished by adjusting the antenna instead.