3/4" VTR's
Here's the short story.
One-inch can record the entire composite signal by using lots of tape (both
in terms of width and speed).
The smaller formats can't do that, so they use various ways of shoehorning
the signal onto the tape. U-Matic, VHS and SVHS all use the same system:
they separate B&W detail information from the color information, convert
the color information to a much lower frequency (at a horrible cost in
terms of color detailing), remix the signals and record them to tape.
Coming back off the tape, the signal is resplit, the color data is
converted back up in frequency, it's recombined and sent on its way. The
formats differ in terms of how much damage is done to the signal in the
process, and since they clobber the signal in different ways, there's some
argument as to whether U-Matic or SVHS is better; VHS is the clear loser.
Betacam, Beta-SP and MII record the signal differently, by splitting it
into luminance and two color-difference signals which are kept separate
throughout the recording process. The color is never downconverted in
frequency, hence, the atrocious artifacts you see in U-Matic, SVHS and VHS
do not occur. These machines are still not quite up to par with one-inch,
but generally only an engineer would notice the difference on the screen.
Then you get into digital formats — D1, D2 and D3, which record the signal
as digital data (so theoretically you can have an infinite number of
lossless generations), but by then we're probably beyond a rational price
for what you're attempting.
Hope this helps.
Pete