Model 900CT & 900BT instruments are single channel; 8-pole low-pass or high-pass front panel tunable filter instruments. The controls allow the user to select a corner frequency between 0.1 Hz and 49.9 kHz with a resolution of 1:499 for each of the four selectable ranges.

The instrument exhibits an input impedance of 1 M shunted by 47pF to a single ended signal source. When configured in the differential mode, the instrument has a common mode rejection ratio (CMRR), which exceeds 60dB; in this mode the instrument presents an input impedance of 2 M's shunted by 47pF to a double-ended single source. Front panel gain control also enables the operator to select a gain factor of 0, 10, or 20dB.

Standard operational features include:

1. Adjustable Frequency Control
2. Differential Input Amplifiers
3. Adjustable Gain Control
4. Off-set Adjustment
5. BypassControl
6. BNC ConnectorsforSignal l/O