Tektronix ECO422D Instruction Manual page 83

Performance Verification
Set the step attenuator to 0 dB of attenuation.
Set the TG700 BG7 to output an NTSC black burst signal.
Press Reset.
CHECK - - that there are no errors shown for either the Primary or Backup
ECO422D sync sources.
Set the ECO422D to "Backup" Sync Source and Auto Switch to "Switch on
Fault."
Add attenuation, 0.5 dB at a time, to the Backup input signal until the signal
source switches to the Primary.
Press the Reset button on the front panel and try to return the signal source
to Backup.
CHECK - - that the Backup signal still shows an error and automatically
switches back to Primary. If the ECO422D does not continue to show the
Backup signal in error after the reset, continue adding attenuation until the
Backup signal switches to Primary again.
CHECK - - that the ECO switches between 2 and 4 dB down.
5. PAL Black Burst Check for Channel 1 Backup
Switch between 2 and 4 dB down from nominal
Connect the equipment as shown in Figure 5- -1, except swap the Backup and
Primary input signals at the ECO422D, so that the step attenuator is on the
Backup input signal.
Set the Channel Configuration switches to Disabled (signal not checked) for
all channels (set all the DIP switches on S2 through S11 to "open").
Set the Channel Configuration switch to PAL Black Burst for Channel 1 (set
S1- -1 to "open," S1- -2 "closed," and S1- -30 through S1- -8 "open").
Set the step attenuator to 0 dB of attenuation.
Set the TG700 BG7 to output a PAL black burst signal.
Press Reset.
CHECK - - that there are no errors shown for either the Primary or Backup
ECO422D sync sources.
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ECO422D SD/HD Changeover Unit Instruction Manual