Gamma
You probably already have a good NTSC monitor, a TV set. Remember, your tapes
aren't likely to be ultimately viewed on $10,000 monitors – just plain old
TV's. So your effort should be put into making images look as good as possible
when viewed on plain old TV's. I'd be willing to bet that the monitor at an
electronics store is nowhere near accurately calibrated. Take a TV, and try to
rent a colorbar generator and get a book or some advice on adjusting the
display from the reference signal (by eye). This will get you close for little
money. Tape the knobs on the TV or whatever to make sure they stay at the
calibrated positions.
BILL