Loop through schematic - any information?

[R110]

video loop thrugh schematic

Hi all
Does any one have any information about loop through block of the input section in video distributer systems.
Thanks in advance
R110

 

[House_Cat]

loop through circuit

Loop-thru is generally just what the name suggests. The input connector is jumpered to a second connector to allow the signal to continue on to another device.

There isn't much of a circuit there. The input connector either is directly soldered to a circuit board, or there is a short piece of coax connecting to the distribution amp circuitry.

There is a second piece of coax, or a trace going to a second connector (the loop-thru connection). These internal jumpers are kept as short as possible. Sometimes they are terminated at the connector with a resistor that matches the characteristic impedance of the recommended cable.

Loop-thru is almost always passive. In some high end equipment, there may be a 1:1 broadband amp for signal isolation. Seldom is there any stage with gain added to the loop-thru connection.