Krohn Hite 3900 Low Pass Filters
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Refurbished Krohn Hite 3900
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Krohn Hite 3900 Details
Krohn Hite 3900
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.
