The dual TAD202 incorporates both tracking and system delay to synchronise video and audio sources.

Ideal uses include on broadcast station and OB lines in where video synchronisers with associated audio feeds are in use, by broadcasters wanting to make live adjustments to lip sync, as a low-cost way of delaying analogue audio, or where audio delay is required as part of A to D or D to A conversion.

The system fixed delay is used for the manual addition of large amounts of delay, and can be set between 0 and 680ms.

The difference in output frequency relative to input frequency is adjustable in steps from 3.2% to 0.05%, with a 0.05% change resulting in minor audio distortion and therefore allowing live adjustment.

In tracking mode TAD202 matches audio delay to the video delay of any synchroniser with TTL tracking pulse outputs tracking over a range of 40ms.

The fixed delay (between 10 and 640ms in tracking mode) is generally set first, with the TAD then intelligently tracking in a predictive manner based on the synchroniser's current performance, pre-compensating for the addition or drop of a video frame to minimise lip-sync errors that would otherwise result.

On rapidly changing video sources threatening a degradation in audio, the tracking will disable itself and revert to system delay until the video becomes stable again, so as to always maintain the audio quality.

One of the many strengths is TAD202's flexibility. The two stereo inputs and outputs can either be two AES or four mono analogue - configured by the customer using piggybacks.

This reduces the need for multiple versions, as TAD can be either analogue or digital - or a mixture of both, making it an A to D or D to A converter.

TAD202 shares the TANDEM piggybacks, and uses the input HD-AIP2 and HD-DIP2-RS and the output HD-AOP2, HD-DOP2-75 and HD-DOP2-110.

The two stereo channels can be controlled together or separately by either one or two tracking input pulses from the synchroniser. TAD202 locks the digital output to an AES reference, or if no reference can be switched to lock to either TTL pulse input.

It has sophisticated audio error masking with the ability to repair corrupted audio packets, and can accept a wide range of digital audio frequencies, including 44.1kHz sources. Digital output frequency is set to 48kHz.

The stereo channels can be monitored either through the rear module or via a miniature stereo jack socket on the board edge.

Control and status monitoring is available via board edge, or remotely using either the active frame front panel, remote control panel, SNMP or the Statesman PC Control System, while up to 16 presets can be stored.

The TAD202 can be used with two frame rear modules. The single slot RM04 - which allows 24 tracking audio delays in 2U - should be used for analogue or 110 ohm digital audio, while the two slot RM07 should be used for 75 ohm AES.