TASCAM CG-2000

Product overview

The TASCAM CG-2000 is a master clock multi-output precision generator for broadcast stations, post-production facilities and installed audio / video systems, with an OCXO internal clock, redundant references and two power supply circuits.

The flagship of the TASCAM CG series generates video reference and audio clock from a high-precision OCXO (oven-controlled crystal oscillator) that is not influenced by the temperature of the environment. Twelve word clock outputs, four video outputs, two AES3/11 and two S/PDIF outputs feed large synchronisation systems, while A/B video and word clock inputs, holdover, a glitch-free relocking circuit and dual AC inlets keep sync running when a reference or a power circuit fails. An analyser, error logs, an alarm output, presets and user self-calibration make maintenance simple.

Key features

• Two power supply circuits with AC IN A and B for power redundancy
• Video reference and word clock redundancy: A/B inputs, three switching modes and holdover
• OCXO internal clock: ±0.01 ppm accuracy (factory adjusted), ±0.005 ppm per day stability
• 10 MHz input for an atomic (rubidium) or GPS clock for even higher precision
• Jitter management circuit and glitch-free relocking circuit
• 12 word clock outputs up to 192 kHz; outputs 11/12 also x1/4 to x4 Fs and 256 Fs Super Clock
• 4 video outputs: NTSC, PAL and HD tri-level (720p, 1080p, 1080i, 1080PsF)
• 2 AES3/11 and 2 S/PDIF outputs; AES3 and AES11 input as a reference source
• Pull-up/down: 0.1% for 24F and 29.97F, 4% for 24F and 25F
• Analyser for input frequency, phase difference, input level and output termination
• Logs and alarm: error log, CSV operation log to USB flash drive, GPO alarm output
• Four presets with USB import/export, panel lock, 128 x 64 organic EL display, EIA 1U rack size

An OCXO at the heart of the system

The crystal oscillator is the heart of any clock generator. The CG-2000 uses an OCXO for its precision and its independence from room temperature, with a frequency accuracy of 0.01 ppm, which exceeds that of a TCXO, and word output stability of ±0.005 ppm or less per day. For even higher system precision, the WORD/EXT inputs accept a 10 MHz signal from an atomic or GPS clock.

Redundancy for systems that must not stop

Two power supply circuits protect against a power outage on one line, and two inputs each for video reference and word clock protect against a lost external clock. Choose the primary and secondary reference and one of three sequence modes (primary priority, automatic switching or one-way). If every reference is lost, the holdover function sustains the reference frequency from the internal clock, and the glitch-free relocking circuit keeps video and word clock in phase so recovery happens without noise or skipped sound.

Outputs for large synchronisation systems

Twelve BNC word clock outputs cover 32 kHz to 192 kHz with pull-up/down for film and video work, and outputs 11 and 12 can also deliver x1/4, x1/2, x2, x4 or 256 Fs Super Clock. Four BNC video outputs provide SD black burst, composite sync or HD tri-level sync, and two AES3/11 XLR outputs plus two S/PDIF RCA outputs carry the clock on digital audio lines. Word clock output level is adjustable from 1.0 to 3.5 V for each pair, so every device receives an optimum signal.

Troubleshooting and maintenance tools

The analyser measures the input frequency, the phase difference between references, the input level and the termination of the connected devices, so wiring problems are found without separate measuring equipment. Errors are shown on the display and kept in an error log, the operation log can be exported as a CSV file to a USB flash drive, and the 6-pin Euroblock alarm output signals errors to an external indicator. A self-calibration function lets you calibrate the internal oscillator with a 10 MHz or PPS signal from a GPS-based reference.

In the box

• TASCAM CG-2000 master clock generator
• Power cords (x 2)
• Euroblock connectors (x 2)
• Rackmount screw kit
• Owner's Manual (including warranty)

TASCAM CG-2000: frequently asked questions

What can the CG-2000 lock to?

It can run from its internal OCXO or lock to a video reference (A or B), a word clock (A or B), a 10 MHz atomic or GPS signal on the WORD/EXT inputs, or an AES3/AES11 signal.

How does the redundancy work?

With the reference redundancy function on, the CG-2000 switches to a secondary reference if the primary is lost and holds the frequency with its internal clock if both are lost. Two AC inlets allow power redundancy on separate power circuits.

Which video formats are supported?

NTSC and PAL black burst, NTSC B/W composite sync and HD tri-level at 720p, 1080p, 1080i and 1080PsF, at frame rates from 23.976 to 60 depending on the format.

Can the internal oscillator be calibrated?

Yes. Feed a 10 MHz signal generated from GPS, or a PPS signal, into the CALIBRATION INPUT and the unit calibrates its internal clock. This needs a separate PPS-output 10 MHz oscillator with a built-in GPS antenna.

Where can I buy the TASCAM CG-2000 in India?

The TASCAM CG-2000 is available from Shivansh Electronics, Kolkata, West Bengal, India, with delivery across India.

Workflow 1: Broadcast master clock with redundancy

Keep a broadcast facility in sync even if a reference or a power line fails.

Connections

Setup

1. Connect both power cords and set POWER RED. to ON on the UTILITY 1 page.
2. Select VIDEO A as the reference and turn REDUNDANT on with VIDEO B as the secondary.
3. Choose the sequence mode, for example PREF. PRI. to return to the primary as soon as it recovers.
4. Save the setup to a PRESET button so it can be recalled at any time.

Tip: The REFERENCE REDUNDANT and POWER REDUNDANT indicators show at a glance that both paths are working.

Workflow 2: Post-production video and audio sync

Lock picture and sound equipment in an editing or mixing suite to one clock.

Connections

Setup

1. Set the video format and frame rate on the VIDEO CLOCK page.
2. Set the audio clock frequency on the AUDIO CLOCK page.
3. Set WORD 11/12 to x256 (Super Clock) for equipment that needs it.
4. Apply 0.1% or 4% pull-up/down for film and video work when required.

Tip: Turn on AUTO RATE to follow the frame rate or sample rate of an incoming reference automatically.

Workflow 3: Locking to an atomic or GPS reference

Build a system with even higher clock precision.

Connections

Setup

1. Connect the 10 MHz reference to a WORD/EXT input with the correct termination.
2. Select WORD A as the reference on the REFERENCE page.
3. Check that the LOCK and SIGNAL indicators are lit.
4. Confirm the WORD IN 10MHz status on the INFORMATION screen.

Workflow 4: Installed audio / video system

Synchronise digital audio devices across a large installation from one 1U unit.

Connections

Setup

1. Mount the CG-2000 in a 1U rack space with the supplied screw kit.
2. Run the clock cables to each device and set the WORD OUT LEVEL per pair to suit the cable runs.
3. Use ANALYZE > TERMINATION to check that each output has a single termination.
4. Wire the alarm output so errors are reported to the monitoring system.

Tip: Turn PANEL LOCK on after setup to prevent accidental changes.

Workflow 5: Troubleshooting a sync problem

Find the cause of clicks, dropouts or unlocked devices quickly.

Connections

Setup

1. Press INFO: if it is red, read the current errors on the ERROR INFORMATION screen.
2. Open ANALYZE to check input frequency, phase difference and input level of the references.
3. Check the termination results of the word outputs (OPEN, SINGLE or OVER).
4. Export the operation log as a CSV file with LOG EXPORT for a closer look on a computer.

Workflow 6: Calibrating the internal oscillator

Keep the OCXO at its best over years of operation.

Connections

Setup

1. Keep the CG-2000 powered for a long time so the internal oscillator is stable.
2. Set the GPS termination on the TERMINATION page (50 Ω by default).
3. Connect the 10 MHz or PPS signal to the CALIBRATION INPUT.
4. The unit recognises the signal automatically and calibrates its internal clock.

Tip: Calibration needs a separate PPS-output 10 MHz oscillator with a built-in GPS antenna.