HU-TX500-TECH
75
TX500 series technical manual
5.2.4 Line and Fraction adjustment
For the three video inputs to be synchronised for keying and mixing, they must each lie
inside their one line timing window. This is shown in the following diagram.
The auto-phasing timing window may be thought of as a variable one line delay through
which each SDI input passes. Once all the inputs are centred within their window the amount
of delay is automatically adjusted for each input to give constant output timing. This will hold
true despite changes in input timing, providing those changes remain within the correction
window range. Larger changes in input timing can only be accommodated by re-adjusting
the internal reference timing to bring all the inputs back inside the timing windows. This is
achieved by pressing auto-time or by adjusting SW 7 and SW 6 until all the Range LEDs
illuminate green.
It is not recommended to use Auto time in the TX frame due to the system operation. It is
normally best to set the timing as early as possible and NOT in the middle.
Note: The delay through a single card is
⅛
of a line therefore it is advisable to set the mixer
card to the earliest possible timing to allow the 4
th
Keyer card, where used, ½ line flexibility
for the Key and Fill inputs.
