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QAM/8VSB Dual Monitoring Blade


The VB262 QAM/8VSB input blade offers monitoring of QAM signals as found in cable networks and digital terrestrial signals found in 8VSB networks. Each VB262 blade has two independent tuners. One is enabled by default and the other is enabled with the VB262RF-LICENSE.

A chassis can be equipped with a single VB120 or VB220 controller blade that has one or two VB262 QAM input blades under its control. The complete configuration with the fully licensed VB120 provides real-time monitoring and alarming for four QAM or 8VSB RF inputs, 50 IP MPTS/SPTS multicasts and one ASI TS input. ETSI TR 101 290 analysis is performed in parallel for RF inputs, the ASI input and the IP input. If the VB220 is used as the controller card, the IP monitoring capacity is increased to 260 MPTS/SPTS multicasts in addition to the RF inputs.

The combined unit is ideal for hybrid networks where IP is used as a carrier from head-end to the regional edge-multiplexer/modulator/transmitter. The built-in round-robin functionality allows sequential analysis of multiple QAM or 8VSB multiplexes, making it possible to monitor the total broadcast contents of a cable transmission system using a single VB262.
By running in spectrum sweep mode, the VB262 module is further capable of measuring analog signal levels, in effect offering the operator a basic frequency analyzer function at the deployment location.

  • Dual input QAM/8VSB receiver (one input standard, the second is optional)
  • Fully independent inputs
  • Fully compliant with ETS 300 249
  • ITU.T J.83 (Annex A/B/C)
  • QAM modes: 16,32,64,128,256
  • VSB modes: 8VSB
  • Constellation Diagram
  • Wide symbol rate range of 0.87 to 7.0 Mbaud
  • Selectable IF filter (6/8 MHz)
  • Excellent neighbor channel isolation
  • Dual 75 ohm F-connector input
  • SNR
  • Pre-FEC BER
  • Post-FEC BER
  • MER
  • Input signal level
  • Frequency offset
  • Symbol rate offset
  • Spectrum inversion
  • AGC Lock/Carrier lock indication
  • Inputs support round-robin operation
  • Fully controlled via backplane by VB120 or VB220
  • Hybrid RF/IP networks 
  • Remote QAM signal monitoring 
  • Remote monitoring of DTT signals

Frequency range: 51 - 1003MHz
Symbol rate: 0.87 - 7.0Msym/s
RF power level: -60dBm to -10dBm (+/-1.5dB)
SNR*: < 42dB (+/-2dB)
MER: < 42dB (+/-2dB)
BER pre-FEC: > 1.0E-8
BER post-FEC: > 1.0E-9
Input sensitivity: -60dBm
* minimum signal level for maximum MER is -45dBm

Dual 75Ω F-connector, female

Standard 19˝ 1RU rack-mount
W x H x D: 19 x 1.7 x 15.75in. (483x43x400 mm)
Weight: 9.3 lbs (4.2 kg) fully populated

Operating temperature: 0°C to 45°C
Storage temperature: -20°C to 70°C
Operating humidity: 5% to 95% non-condensing

Fully controlled through backplane
Accessible through master VB120 or VB220 user interface

Draws power from backplane (+5V)
Maximum 5W dissipated per card