Changeover Unit
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Features & Benefits

  • Switches Analog Black and Serial Digital Video, Both Standard and High-definition, and Digital Audio
  • Eleven User-configurable Signal Channels
  • Amplitude Detection on All Channels
  • Electrical Fast Switch Function for Input Channels 4 to 6, with Option ELSW
  • Automatic or Manual Operation
  • Fault and Operating Mode Front-panel Indicators


  • Provides Complete Fault Tolerance when Used as a Switch Between Primary and Backup SPGs or TSGs

The ECO422D is a highly versatile sync changeover unit designed for use in a serial SD/HD digital television environment. The ECO422D will accommodate component or composite serial digital video signals, AES/EBU digital audio, tri-level sync, and analog black-burst signals. This flexibility makes the ECO422D ideal for both the mixed-format and all-digital television facility.

The ECO422D provides eleven user-configured channels, each channel consisting of primary and backup inputs, and an output.

  • Six channels can be set for high-definition serial digital video, standard-definition serial digital video, AES/EBU digital audio, tri-level sync, and PAL or NTSC analog black burst
  • Five channels may be set for standard-definition serial digital video, AES/EBU digital audio, tri-level sync, and PAL or NTSC analog black burst

Channel configuration is by internal DIP switch. Signal amplitude fault detection level follows the setting of the channel configuration switches. Detection on individual channels may be disabled, giving the option of disabling changes to the backup unit on failure of signals not critical to the facility operation.

When operated in the switch-on-fault mode, the ECO422D will automatically select the backup sync source should any of the primary inputs fail. However, in the unlikely event both sync sources are faulty, the ECO422D will not alternate between the two sources. If necessary, this function may be overridden with the manual sync source selection. Manual source selection also facilitates periodic testing of the changeover function. Switching is by mechanical relay with all channels switched simultaneously.

The Electrical Fast Switch function, available with Opt. ELSW, improves the changeover switching speed between inputs, and replaces the mechanical relay on channels 4-6. Using this type of switch minimizes disturbance when switching between primary and backup inputs. With Opt. ELSW, channels 4-6 can only accept a black-burst or tri-level sync signal.

Front-panel controls are provided for source selection, operating mode, resetting the fault indicators, and for disabling the front-panel controls. LED indicators are also provided. Indication of fault and unit on line is also available through the remote connector.




Inputs and Outputs

Return Loss -

Channels 1-6:

30 dB, 0 to 10 MHz.

15 dB, 10 to 750 MHz.

10 dB, 750 MHz to 1.5 GHz.

Channels 7-11:

30 dB, 0 to 10 MHz.

15 dB, 10 to 270 MHz.

12 dB at 360 MHz (15 dB typical) when selected.

Channels 4-6 (with Opt. ELSW):

30 dB, 0 to 10 MHz.


Insertion Loss -

Channels 1-6: 0.2 dB, DC to 10 MHz.

In a frequency range of 10 MHz to 1.5 GHz, the instrument approximates less than 20 meters of Belden 1694A cable.

Channels 7-11:

0.2 dB, DC to 10 MHz.

0.5 dB, 10 to 200 MHz.

1.0 dB, 200 to 360 MHz.

Channels 4-6 (with Opt. ELSW):

0.3 dB, DC to 10 MHz


Maximum Switched Voltage -

All channels:

±5 V

Channels 4-6 (Opt. ELSW):

±1 V (only for the tri-level sync and analog black-burst signals).


Maximum Switched Current - 100 mA.

Crosstalk (Unselected input to output or channel to channel) -

Channels 1-6:

-60 dB to 10 MHz.

-30 dB to 1.0 GHz.

-20 dB to 1.5 GHz.

Channels 7-11:

-60 dB to 10 MHz.

-30 dB to 200 MHz.

-15 dB to 360 MHz.

Channels 4-6 (Opt. ELSW):

-55 dB to 10 MHz.

-45 dB to 30 MHz.


Relay Switch Time - Time that it takes for the relays to switch and settle. Approximately 10 ms.

Channel Switch Time (Channels 4-6, Opt. ELSW only) - Time that it takes for the channel to switch and settle. Approximately 100 ns.

Amplitude Detection - The ECO422D will determine a fault condition exists when the input signal is less than 2 dB from the nominal level. The following are the amplitude ranges for the various types of input signals that will result in a fault condition.

Black Burst -

NTSC: 180 to 225 mV.

PAL: 190 to 235 mV.

Tri-level: 150 to 210 mV.


Serial Digital Video - 505 to 630 mV.

AES/EBU Digital Audio - 630 to 790 mV.

Power Source

Mains Ranges -

Voltage: 100 to 240 VAC, ±10%.

Frequency: 48 to 62 Hz.

Power consumption: 25 W maximum.



Temperature -

Operating: 0 °C to +40 °C, IEC1010-1 compliance.

Nonoperating: -40 °C to +65 °C.


Altitude -

Operating: To 6562 feet (2000 meters), IEC1010-1 compliance.



EMC - Certified to the EMC Directive 89/336/EEC.

Safety -

Approved to: UL3111-1, CAN/CSA-C22.2 No.1010.1.

Complies with: EN61010-1, IEC1010-1.


Physical Characteristics























Last Modified: 2011-09-30 05:00:00

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