both. There are
advantages and disadvantages to either one.
LTC (Longitudinal Time Code) is a continuous signal recorded either on
the tape's address track or on an audio track. The higher end formats
like D2, Beta SP and 3/4 " have an address track devoted exclusively to
Time Code onto which LTC is recorded. On 1/2" tape formats such as
VHS and SVHS, there is no separate address track so LTC is recorded onto
Channel 1 and appears as a consistent, pulsing tone on a VU meter. An
advantage to LTC is that it can be laid down after the fact and changed
without damaging the original dub. However, on 1/2" tapes you lose one
of your audio tracks which is fine if you only have one mono track of dialogue.
Most tape decks have difficulty reading LTC at slow speeds
and not at all in freeze frame.
VITC (Vertically Integrated Time Code) is recording on the horizontal
position bar between video frames. This means that VITC can only be
inserted when the dub or transfer is in progress. One of VITC's faults
is that it at times becomes unreadable when searching at high speeds.
I was told once that VITC can also bleed into the video frame but I have
never heard or seen it happen.
Although I don't know what tape format you are transferring to, if you
are creating transfer masters from tape or film I would use matching
VITC and LTC assuming that your masters have address tracks. Most labs
will do this automatically. I'm assuming that your window burns will
be for viewing on a regular VCR. If this is the case, there shouldn't be
any TC on your dubs. That is the reason for having the window burn, so
that you have the visual matching TC reference numbers without being
forced to use a deck that reads TC.