A word to the wise.
I know how we all religiously terminate our 50 Ohm cables with a 50 Ohm load...... don't we.....????
Well sometimes we forget, or are just doing a quicky check and fail to use, or notice,? the termination (if it's not already internal to the target equipment).
As I just discovered, by chance, that is a no-no for the marker output of the TG501..... if you do not terminate in 50 Ohms (or whatever), you don't get an output at all, or at least just a very tiny one!
This had me chasing around the TG for a couple hours trying to find a fault that didn't exist. I couldn't get any marker through the diode gate before the BNC. The diodes tested good and there were no shorts to ground to be found. Plenty of pulse amplitude up-stream of the gate but nothing (well less than 50mV) arriving at the BNC socket. Something made me put a 50 Ohm term on the socket/cable and hey presto a full amplitude pulse got delivered into the target module.
Summary; the TG501 will output "nothing" without a 50 Ohm term somewhere on it's output socket. I didn't find anything in the manual that specifically said that would be the case, only the obvious "... use a 50 Ohm cable and termination"; obviously good practice, but missing out the critical "MUST USE" about termination. The trigger output does not seem to have the same criticality; it delivers regardless of termination.
