VPR6 1

Another view of what a 'proper' video tape recorder once looked like.

This particular example, having spent its working life together with a VPR80 in a rack /
console, has unfortunately lost its decorative cladding and heavy duty carrying handles -
anyone have any to spare? This makes moving this system a bit tricky, as this machine is a
two (strong) man lift.

One inch C Format machines are what are known as 'direct colour recovery' video
recorders, which means that they have enough bandwidth to record the whole of the 5 Mhz
composite colour video signal directly onto tape without any 'mucking about' that lesser
analog (and digital?) systems do. (VHS for instance has less that half the bandwidth, and
half the resolution of one of these machines.)

With lesser analog systems, horizontal resolution figures were / are often quoted in place of
their rather poor video frequency responses: 240 lines for VHS, 300 lines for SP Umatic,
and 400 lines for S-VHS and Hi-8. By contrast, C Format bandwidth is flat to above 5Mhz
and this equates with a resolution approaching 600 horizontal lines. Though one will need a
very good monitor indeed to enjoy this level of performance.

However, while this is a wideband recorder and the transport a fine piece of engineering,
moving a very thin flexible one inch ribbon of plastic against a wheel rotating at 3,000 RPM
will introduce inevitable small timing errors. Unfortunately any slight instability will
adversely effect the colour reproduction on playback, and therefore electronic correction of
the off-tape video signal is required to obtain a stable broadcast quality colour picture. (In a
studio environment the machine and its output will also need to be 'locked' to 'station syncs'
as well.) This timing correction and synchronization is provided by a complex piece of
electronics called a timebase corrector (TBC), which is mounted under the main machine in
the

above photo. The other box below the TBC is just a signal monitoring and switching unit.

It is important therefore if you are looking for a C Format recorder, to make sure that the
machine comes with a correct TBC - otherwise YOU WILL NOT BE ABLE TO PLAY
BACK COLOUR PICTURES (or be able to do any slo-motion effects as well).

Click on the image above for more pictures.