For the Longitudinal Balance test:
1. What is the output circuit impedance?
2. What is the measurement circuit input impedance?
1. The output impedance of the AT testers is largely irrelevant as Voltech trim the signal level at a connected transformers terminals. For information however, it is 50 ohms on the AT3600 and 20 ohms for the ATi.
2. The measurement channel input impedance is ~2 MOhms.
The selected values of the components RS and RL are placed onto the fixture by the user in all practical situations these values are so low that the measurement impedance has no significant effect.