Tektronix SPG8000 - Master Sync / Master Clock Reference Generator

Master video synchronization and time reference generator

The base configuration includes three sync outputs that can be configured with independent output formats (NTSC/PAL black burst and/or HD tri-level sync) and independently adjustable timing offsets. With the BG option, four more analog outputs can be added. A high-accuracy, oven-controlled crystal oscillator provides a stable frequency reference for the system, or the pass-through genlock input can be used to lock to an external video reference or 10 MHz continuous wave signal.

The SPG8000’s Stay GenLock® feature avoids “synchronization shock” if the external reference suffers a temporary disturbance, by maintaining the frequency and phase of each output signal. When the external reference is restored, Stay GenLock® ensures that any accumulated clock drift is removed by slowly adjusting the system clock within standard limits instead of “jamming” back to the correct phase.

Time reference outputs are available in multiple formats. Three independent linear time code (LTC) outputs are available, and a fourth LTC connection can be used as input or output. Each LTC output has independent frame rate selection, time source (time-of-day or program time) and time zone offset. Vertical interval time code (VITC) is available on each NTSC or PAL black output, also with independent time sources and offsets. The SPG8000 can also serve as a Network Time Protocol (NTP) server, providing the time-of-day reference to network-attached devices.

Optional GPS/GLONASS receiver

The GPS option adds an internal receiver to the SPG8000 that is capable of receiving both GPS and GLONASS signals. When connected to an external antenna that supplies the standard GPS and/or GLONASS RF signal (for example, SPG8000ANT), the SPG8000 can use the GPS⁠/⁠GLONASS system’s stable frequency reference.

The GPS/GLONASS signal also includes a precise time-of-day reference that can be used for all time code outputs. Similar to the Stay GenLock® feature, the SPG8000 can maintain the video frequency and phase when the GPS/GLONASS signal is interrupted, and the Holdover Recovery mode will ensure a shock-free realignment of frequency and phase when the GPS/GLONASS signal is restored.

Test signal outputs

The SPG8000 can be optionally configured with a variety of test signal outputs. Option BG includes two composite analog outputs (NTSC or PAL) that can be used to generate test patterns such as color bars, or serve as additional black burst outputs.

Option SDI adds two fully independent serial digital video generator channels of two outputs each. Each channel can be configured to any standard SD or HD-SDI format and frame rate. The selected test pattern can be generated on both outputs per channel, or one output can generate digital black. Option 3G extends the functionality of the SDI test signal outputs by adding 3 Gb/s SDI formats.

A wide variety of standard test patterns are included, such as color bars, convergence grid, step scales, ramps, multiburst, SDI pathological test matrix and a real-time programmable zone plate generator. Bitmap images can be downloaded to the SPG8000’s flash memory for arbitrary user-defined test patterns. ID text, burn-in time code, circle, and color logo overlays can be added to any test pattern, and several ancillary data packet types, including ancillary time code and user-defined packets, can be inserted into the SDI output signal.

Audio reference signals

Several audio reference signals are available on the SPG8000. The base configuration includes a 48 kHz word clock output, and option AG adds five AES/EBU output pairs. One pair is dedicated to a Digital Audio Reference Signal (DARS) output, and the other four pairs are used for test tone generation, with independent tone frequency and amplitude settings for each of the 8 channels.

Audio tone generation is also included with the SDI option, as embedded audio on each of the SDI outputs. Option DBT extends the audio functionality by generating these test tones in Dolby E format. Various Dolby E audio frame start locations can be set to test the error handling ability of the signal processing equipment in the signal path. Embedded Dolby E metadata are also included in the Dolby E test stream. Supported Dolby E program configurations include mono, stereo, 5.1 and 7.1 surround sound audio.

Remote access

The SPG8000 includes a 10/100/1000BASE-T Ethernet interface for remote access to the instrument. A web-based user interface can be used for all configuration settings and for monitoring system status.

Alarm and key status information is also available using Simple Network Management Protocol (SNMP) messaging, enabling easy integration with network management systems. Remote control and alarm reporting is also available using a general purpose interface (GPI). The SPG8000 has a front-panel USB port that can be used to backup and restore presets and other user data, and to perform system firmware upgrades.

Optional backup power supply

For mission-critical applications, the SPG8000 can be configured with a second power supply module. Under normal operation, the designated backup supply is seldom used, ensuring that it has maximum remaining life should the primary supply fail. The backup supply is load-tested once each day to verify that it can serve as the primary supply if necessary.

The usage time of each supply is logged as “temperature-weighted hours”, a metric that best estimates the calculated life of the supply. A front-panel LED will indicate when the supply is nearing its end-of-life.

If the primary supply is interrupted for any reason, the system will switch to the backup without any disruption to system operation. Power supply modules are hot-swappable for easy replacement, and feature a locking mechanism to prevent the power cable from accidental disconnection.