The Krohn-Hite Model 3900 programmable, dual channel Elliptical filter/voltage gain amplifier is one of a family of new programmable filters from Krohn-Hite. It was carefully designed with the user in mind, providing ease of operation, reliability and price competitiveness. All backed with the quality which Krohn-Hite has provided in filters since 1949.
FILTER FEATURES
As an elliptical filter, the Model 3900 has two independent filter channels that have a tunable cutoff frequency range from 1Hz to 99kHz and a rolloff rate of 115dB/octave. Each filter section has a minimum stopband attenuation of >80dB and a passband ripple of typically 0.22dB.
The 3900 provides either a single-ended or differential input with a common mode rejection of >60dB. Input gains up to 40dB in 10dB steps and output gains to 20dB are also provided. The 3900 will accept input signals of ±10V peak at 0dB gain and has selectable ac or dc coupling. The filter is GPIB Bus programmable and is complimented with non-volatile memory for the storage of up to 99 front panel set-ups. Overload detectors are standard and assist the user in detecting excessive input signals or incorrect gain settings.
AMPLIFIER FEATURES
The 3900 is also a programmable voltage gain amplifier for applications that require a low noise amplifier. The amplifier has a bandwidth of 1MHz and gains to 60dB, selectable in 10dB steps, and a wideband noise of <100 V.
APPLICATIONS
Typical applications for the Model 3900 are: anti-aliasing in digital signal processing, separating specific bandwidths of information, enhancing signal-to-noise ratio, low noise pre-amplification and many more. Models offering other types of filters with different frequency ranges, slopes and number of channels are also available.
SPECIFICATIONS
FUNCTION: Two independent, low-pass filter channels or voltage gain amplifiers.
FILTER MODE (Each Channel)
Type: 7-pole, 6-zero elliptical.
Attenuation: 115dB/octave.
Passband Ripple: 0.22dB typical, 0.4dB max.
Tunable Frequency Range fc: 1Hz to 99kHz.
Frequency Control: Keyboard entry or increment, decrement keys.
Relative Gain at fc: –0.22dB at 1.01fc nominal.
Cutoff Frequency Accuracy: ±2%.
Stopband Attenuation: >80dB.
Stopband Frequency (fs): 1.7fc.
Insertion Loss: 0dB ±0.1dB.
Pre-Filter Gain: 0dB, 10dB, 20dB, 30dB, 40dB ±0.2dB.
Post-Filter Gain: 0dB, 10dB, 20dB ±0.2dB.
Input Coupling: ac or dc.
Bandwidth: dc coupled, dc to fc; ac coupled, 0.32Hz to fc.
Wideband Noise (RFI): min. gain, 1kHz cutoff, <400 V, 99kHz cutoff, <1mV; Max. gain, <20 V.
Harmonic Distortion: –80dB at 1kHz.
Intermodulation Distortion: –80dB below full scale volts at 70kHz and 90kHz input frequency.
Spurious Components: –80dB below full scale with input source <50 ohms.
DC Stability: Typically ±10mV/ C.
Crosstalk Between Channels: –85dB below full scale with input source <50 ohms.
AMPLIFIER MODE (Each Channel)
Bandwidth: dc coupled, dc to >1MHz min. gain, >400kHz max. gain; ac coupled, 0.32Hz to >1MHz min gain, >400kHz max gain.
Insertion Loss: 0dB ±0.05dB.
Gain: 10dB to 60dB in 10dB steps ±0.1dB.
Input: Differential or single-ended +(in phase), –(inverted).
CMRR: >60dB to 10kHz; approximately 50dB at 100kHz.
Sensitivity: 10mV peak with 60dB total gain for 10V peak output.
Maximum Input: ±10V peak at 0dB gain reduced in proportion to gain setting.
Impedance: 1 megohm in parallel with 100pf.
Coupling: ac or dc.
Maximum DC Component: ±100V in ac coupled mode.
Output:
Maximum Voltage (o.c.): 7Vrms to 200kHz; 3Vrms to 500kHz; 1Vrms to 1MHz.
Impedance: 50 ohms.
DC Offset: Adjustable to zero volts.
Harmonic Distortion (1V output): –80dB (0.01%) to 10kHz; –60dB (0.1%) to 100kHz..
Wideband Noise (referred to input, 2MHz BW detector): 150 V min. gain; 25 V max. gain.
DC Stability (RFI): Typically ±10mV/ C.
Crosstalk Between Channels: >85dB below full scale with input source <50 ohms.
GENERAL
Phase Match Between Channels: 1 typical, 2 max from dc to 0.8fc; 2 typical, 4 max from 0.8fc to fc.
Amplitude Match Between Channels: ±0.1dB max from dc to 0.8fc; ±0.2dB max from 0.8fc to fc.
Memory: 99 selectable groups; memory is non-volatile battery-backed CMOS.
Overload Modes: Three selectable modes; non-latching, that monitors all channels and displays the first channel to have an overload; latching, that maintains the overload display until it is cleared; and no indications.
Overload Indicators: LEDs for input and output. Gain display flashes when overload occurs on displayed channel.
Input Indicators: Green LEDs to indicate active input BNC.
Self-Test Diagnostics: MPU checks unit upon power-up. Display indicates failure mode.
Displays: 7 segment, green, LED; 0.3" high.
Remote Programming: IEEE-488.1 interface. Subsets: SH1, AH1, T6, L4, SR1, RL1, PP1, DC1, DT0, C0 and E1.
Operating Temperature: 0 C to 50 C.
Isolation to Chassis: ±100Vdc.
Storage Temperature: –20 C to 70 C.
Input/Output Connectors: BNC, front and rear.
Power Requirements: 90-132/180-264 volts ac, 50Hz-400Hz, 40 watts.
Dimensions and Weights: 3.5" (9cm) high, 8.5" (21.8cm) wide, 18" (46.2cm) deep; 12 lbs (5.4kg) net, 14 lbs (6.3kg) shipping.
Accessories: 3-terminal line cord; operating manual.
