6-89RA8GA Adjustable Gain PreAmpRA8GA Adjustable Gain PreAmpRA8GA OverviewThe RA8GA was designed to acquire and digitize multi-channel data from a varietyof analog voltage sources such as eye-trackers, amplifiers (including grass, axon,and WPI amplifiers), PH meters, and temperature sensors. The RA8GA digitizes upto eight channels at acquisition rates of 6, 12, or 25 kHz. All channels have avariable group gain setting of 10 Volts, 1 Volt, or 100 millivolts. The system has abandwidth to DC, which allows users to acquire low frequency DC signals. Inaddition a two-pole low pass filter (12 dB per Octave) is set at 7.5 kHz.Power and InterfaceThe device is powered via the System 3 zBus (ZB1PS) and requires an interfaceto the PC. If the RA8GA is housed in one of several ZB1PS chassis in yoursystem, ensure that it is connected in the interface loop according to the installationinstructions: Gigabit, Optibit, or USB Interface.RA8GA FeaturesMax Input LightsThe Active light flashes once a second when the preamplifier is not connected to abase station. It glows steady when it is properly connected.The 10 V, 1 V, and 0.1 V lights indicate the current acceptable voltage range. If thesignal input reaches -6 dB from the maximum input for the selected range, a clipwarning light on the base station will be lit. On RX5 or RX7 processors the LEDlocated next to the fiber optic input port serves as the clip warning light.Range Select ButtonAll channels use a group adjustable gain control i.e. all channels are either +/- 1Volt, 10 Volts, or 0.1 Volt. A Range Selection button adjusts the gain settingamong the following voltages: 0.1X gain = +/-10 Volts, 10X gain = +/- 100milliVolts, 1.0 X gain = +/-1 volt. Press the button to scroll through the available
