Hello.
I have a Oscilloscope having selection for 1M, 75 and 50 Ohm. And all BNC cable in our lab has characteric impedance of 50 Ohm. Thus I simply thought OSC is always to be 50 Ohm for impedance matching. But when the device (ex: DG535 delay generator) has output impedance of HighZ, people say I have to set Oscilloscope as 1M ohm for not having signal interference, although BNC is still 50 Ohm. Could u tell me how this works? And people even say it is better to equip 50 Ohm terminator to the BNC cable end to prevent reflection. In this case T adapter (instead of in-line type) is used. It looks that T adapter is simply signal divider thus inserting additional load (terminator) to one side of T adapter for impedance matching is...hard to understand. Please help me to clear this confusion.
I have a Oscilloscope having selection for 1M, 75 and 50 Ohm. And all BNC cable in our lab has characteric impedance of 50 Ohm. Thus I simply thought OSC is always to be 50 Ohm for impedance matching. But when the device (ex: DG535 delay generator) has output impedance of HighZ, people say I have to set Oscilloscope as 1M ohm for not having signal interference, although BNC is still 50 Ohm. Could u tell me how this works? And people even say it is better to equip 50 Ohm terminator to the BNC cable end to prevent reflection. In this case T adapter (instead of in-line type) is used. It looks that T adapter is simply signal divider thus inserting additional load (terminator) to one side of T adapter for impedance matching is...hard to understand. Please help me to clear this confusion.