Eyecote
The Jitter / TBE Option is an easy to use PC-based time interval measurement system that makes Jitter and Effect Length measurements according to Philips Orange, Yellow and Red book standards. It measures both jitter and length deviation for all sizes of pits and lands (3T - 11T).
The Jitter Option can be used with either the QA-101 or QA-301 CD Analyzers. If you already have one of these CD Analyzers, it must be modified to work with the Jitter Option. The cost of this modification is included in the Jitter Option price.
The system is very easy to use; all you have to do is run the Windows software, and start the player. Jitter and effect length measurements may be made during a normal test, or independently. The test can be started and stopped at any desired point. The results are displayed in the form of histograms and bar graphs, plus a summary printout.
FEATURES
Why Measure Jitter?
Jitter is a measure of the random variation in pit and land lengths. Jitter is important because the CD information is carried in the edges of the pits. A transition between pit and land (either pit to land or land to pit) is a one, and everything else is a zero. Since the data is self-clocked at a constant rate, if the edges of the pits are not in the correct places, errors will be generated. If a transition between pit and land comes as little as 115 ns early or late, an error will result. A standard deviation of less than 35 ns will result in only about 1% probability of the effect lengths varying by more than 115 ns. Pit distortion, crosstalk from adjacent tracks, intersymbol interference, pit wall steepness, laser noise, and LBR (or CD-R writer) instability can all cause jitter on the disc.
Displays
Histograms of 3T - 11T pit and land lengths give a graphical representation of the lengths of all pits and lands. You can get a good idea of the disc quality from this graph by observing the widths of the lobes. Obviously, when lobes overlap, error will be generated.
The jitter bargraph shows the standard deviation (jitter) for each pit and land length.
The length deviation graph shows the deviation of the pit and land lengths from their ideal values.
System Requirements:
• IBM PC compatible (‘486 or Pentium)
• VGA graphics
• One available 8-bit ISA slot
• Windows 3.1 or Windows '95
