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BNC Inputs / Output, insulated or
screened type. Routed via changeover RF relay (<1dB
loss @ 900Mhz) providing termination of unused input,
defaults to Main input on power loss.
External connectors are PCB mounted, a 16 way IDC
connector inside provides for power and control connections.
Each board is capable of Video changeover selection
to one of ten control lines, via DIP switches.
The control input is dioded before the DIP switch
and opto-isolated from the drive to the relay, thus
the switching current is low and should not suffer
from interference when the relay operates.
Notes:
Signal core of each input BNC is switched either to
the output BNC or to a 75R terminating resistor, thus
the unused input is always terminated.
The shield, outer, of each BNC is commoned via the
relay block providing screening within the relay itself.
The outer is NOT switched.
It is proposed to fit the insulated type of BNC to
isolate the BNC common from the chassis of the unit
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