INTRODUCTION
The Krohn-Hite Model 3901 programmable, two 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 3901 has two filter
channels that have a tunable cutoff frequency
range from
1Hz to 99kHz and a rolloff rate of 115dB/octave. Each
channel can be used independently;
one as a high-pass
filter and the other as a low-pass filter; or the
channels can be externally
connected
for band-pass
(series) or band-reject (paralleled) operation. Each
filter section has a
minimum stopband
attenuation of
>80dB and a passband ripple of typically 0.22dB.
The 3901
provides either a single-ended or differential input with
a common mode rejection of
>60dB.
Input gains to 40dB
in 10dB steps and output gains to 20dB are also provided.
The 3901
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
3901 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
<100µV.
APPLICATIONS
Typical
applications for the Model 3901 are: anti-aliasing in
digital signal processing, separating
specific
bandwidths
of information, enhancing signal-to-noise ratio,
distortion testing, 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.
FUNCTION
Two independent filter channels. Channel 1, high-pass or amplified
by-pass; Channel 2,
low-pass or
amplified by-pass; one channel of band-pass or
band-reject with external connections.
FILTER MODE
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: Keypad entry or increment, decrement keys.
Bandwidth:
High-Pass: fc to upper 3dB cutoff, >500kHz at 1Vrms with 0dB
gain.
Low-Pass: dc coupled, dc to fc; ac coupled, 0.32Hz to fc.
Relative Gain at fc Low-Pass: –0.22dB at
1.01fc nominal; High-Pass: –0.22dB at 0.99fc nominal.
Cutoff Frequency Accuracy: ±2%.
Frequency Resolution: 1Hz, 1Hz to 99Hz; 10Hz, 100Hz to 990Hz; 100Hz,
1kHz to 9.9kHz;
1kHz,
10kHz to 99kHz.
Stopband Attenuation: >80dB.
Stopband Frequency (fs): Low-Pass, 1.7fc;
High-Pass, 0.59fc.
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.
Wideband Noise (RFI): min. gain, 1kHz cutoff, <400µV, 99kHz cutoff,
<1mV; Max. gain, <20µV.
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): 100µV min. gain; 20µV
max. gain.
DC Stability (RFI): Typically ±10mV/°C.
Crosstalk Between Channels: >85dB below full scale with input source <50
ohms.
GENERAL
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, 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: 3.5" (9cm) high, 8.5" (21.8cm) wide, 18"
(46.2cm) deep.
Weights: 12 lbs (5.4kg) net; 14 lbs (6.3kg) shipping.
Accessories: 6 foot, 3 terminal line cord; operating
manual.
OPTIONS
Rack Mounting Kit:
Part No. RK-37, permits installation of the Model 3901 into a standard
19" rack
spacing.
Band-Reject Kit: Part No. BR-30, connectors and cables to adapt two
channels for series
(band-pass)
or parallel (band-reject) operation.
Extended 1 Year Warranty: Part No. EW3901.
OPTIONAL ACCESSORIES
CAB-010:
GPIB Cable with
Connectors, 2-Meters
CAB-011:
GPIB
Cable with Connectors, 1-Meters
CAB-025:
Cable, BNC, 3ft, Low Noise
Specifications apply at 25°C ±5°C.
Specifications subject to change without notice.
