Loop through schematic - any information?

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

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.