DESCRIPTION
The Krohn-Hite Model 35 Tunable Active, Low-Pass Filter Card
is the first programmable filter of its
kind to cover the
wide frequency range of 170Hz to 25.6MHz with 2 digits of
resolution. The Model
35 is a 4-pole, maximally flat (Butterworth) filter, with an attenuation slope of
24dB/octave and a
stopband attenuation of 100dB referred
to 1Vrms input.
FEATURES
The filter
card has selectable AC or DC coupling and selectable 1M
or 50 ohm input impedance.
Programmable input gains of up
to 20dB and output gains up to 26dB are standard.
The Model 35 also has the
capability to be configured in an Amplifier By-Pass mode
to operate as
an amplifier, by-passing the filter. This
gives the user the ability to amplify without filtering
when so
desired.
SYSTEM
CAPABILITY
The Model
35 filter card is part of an ever expanding line of
filter cards used to create a filtering
system when
plugged into mainframes Model 3905B/3905C
(3 1/2" high
which will accept up to 5
filter cards) and the Model
3916B (which will accept up to 16 filter cards).
SPECIFICATIONS
FILTER CHARACTERISTICS
Filter Type:
4-Pole, Butterworth, Low-Pass.
Tunable Cutoff Frequency Range: 170Hz to 25.6MHz.
Cutoff Frequency Accuracy: ±2% to 2.56MHz, ±5%
to 25.6MHz.
Frequency Range and Resolution:
|
Cutoff
Frequency Range |
Resolution |
|
170Hz
to 2.56kHz |
10Hz |
|
2.6kHz
to 25.6kHz |
100Hz |
|
26kHz
to 256kHz |
1kHz |
|
260kHz
to 2.56MHz |
10kHz |
|
2.6MHz
to 25.6MHz |
100kHz |
Attenuation
Slope:
24dB/Octave.
Passband Response: ±0.2dB up to 2.56MHz, ±0.5dB
up to 25.6MHz.
Stopband Attenuation: 100dB to 1MHz, 80dB at
10MHz, 70dB at 30MHz, 60dB at 50MHz,
50dB to 100MHz.
Amplified Bypass Mode Bandwidth: >50MHz.
Amplified Bypass Mode Rise and Fall Time: <7ns
with 0dB input gain 6dB output gain,
<10ns with +20dB
input or output gain. <5% ringing or overshoot.
INPUT
Input/Output
Coupling: AC or DC. AC coupling cutoff is
approximately 16Hz at the input
and 10Hz at the output
with a 50 ohm
termination.
Note: The internal 50 ohm input termination is before
the AC coupling.
Impedance: Selectable 1M ohm or 50 ohms, ±2%, shunted by 45pF.
Gain (Pre-Filter): 0dB, +10dB, +20dB ±0.1dB.
Maximum Signal: ±1.5V peak with 0dB input gain,
reduced in proportion to input gain selected.
Maximum Input Without Damage: 12Vrms with input
terminator OFF, 7Vrms with input
terminator ON.
Input DC Blocking Voltage: 200V. Note:
that the internal input termination is before the
AC
coupling and can only tolerate 7Vrms when ON.
OUTPUT
Maximum
Signal: ±3V peak open circuit, ±1.5V peak into 50 ohms.
Gain (Post-Filter): 0dB, +6dB, +20dB, +26dB,
±0.1dB.
Impedance: 50 ohms ±2%.
Distortion (1Vrms sinewave): >–60dB
below signal up to 100kHz (0.1%).
All harmonics
below 50dB to 1MHz; below 40dB above 1MHz.
Output DC Offset: Adjustable to Zero.
Output DC Offset Drift: ±0.5mV/°C referred to
input.
Noise Spectral Density (10kHz to 100MHz referred to
input): Below –128dBm/Hz into 50 ohms.
This translates into a
wideband noise power or voltage for a 30MHz BW of below
–53dBm or
0.50mVrms referred to input.
Spurious Signals: Below –80dBm to 65MHz;
below –75dBm to 100MHz. Referred to input,
represented in voltage form: 22µV and 40µV
respectively.
GENERAL
Input/Output
Connectors: BNC.
Power: 8 watts.
Weight: 1.75 lbs. (.8kg) net.
Operating Temperature: 0°C to 50°C.
Accessories: Operating manual.
OPTIONS
005:
Replace Butterworth response with Bessel response.
Extended 1 Year Warranty: Part No. EW35.
Specifications apply at 25°C ±10°C.
Specifications subject to change without notice.
NOTE:
Model 35 filter card must be used with the Model 3905B/3905C
or
3916B/3916C Mainframe Chassis.
Copyright ©
March 01, 2006
Krohn-Hite Corporation. All rights reserved.
15 Jonathan Drive, Unit 4, Brockton, MA 02301-5566 U.S.A.
Tel: (508) 580-1660; Fax: (508) 583-8989; info@krohn-hite.com
