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- Set the oscilloscope time base to 10ms and the deflection to 1V per divison.
- Remove the input amplifier from the system backplane (if the top and bottom mounting screws are released the module can be simply pulled out).
- Move the jumper link at the front of the board (J1 on the version 2.1 of the board) from current measuring mode ( I ) to positive voltage measuring mode ( + ).
- Replace the amplifier in the system box ensuring full contact (it should not be necessary to tighten the screws).
- Connect a BNC lead from the output of the front panel to the input of the amplifier.
- Connect a second BNC lead from the output of the amplifier to the oscilloscope.
- With the rotor spinning at 32 Hz, the trace on the oscilliscope (when triggered to the incoming signal) should appear similar to Fig (A) below. The output from the front panel produces a brief TTL +5V pulse once per rotor revolution. This pulse will appear as a signal for the filter position at which it occurs with the other positions having no signal. The height of the signal for filter position 1 should vary as gain is varied.
- The jumper can then be reset to its normal current measuring setting and the input amplifier resecured.