FILTER
Passive Audio bandpass Filter
7443 Series
The 7443 series are passive bandpass filters which have been designed for safety
critical applications. They are used in signalling, monitoring and supervisory sys-
tems where the information is carried by signals, typically in the audio frequency
band. The filters are designed to operate over the range of temperature experi-
enced in a non air-conditioned, unheated vehicle exposed to the temperature
extremes found anywhere in North America.
•
The safety critical design feature provides that the output signal level falls
by at least 18 dB below normal if any internal component becomes shorted
or opens.
•
The filters are mounted in hermetically sealed steel cans. These provide a
long life under adverse environmental conditions including high relative
humidity.
•
The temperature stability is maximized by prolonged temperature cycling, prior to tuning, to reduce the disaccommodation factor
of the ferrite core materials. In addition, capacitors are selected whose temperature coefficient of capacitance is the inverse of the
temperature coefficient of inductance of the coils or transformers.
•
All filters tolerate 350 volts peak-to-peak at frequencies outside the pass band.
•
The filters are fitted with an octal plug to make the input and output connections. The filters have four 8-32 studs to provide
secure mounting and withstand vibration.
MECHANICAL
(All dimensions in inches)
ELECTRICAL SPECIFICATIONS @ 25˚C
Center frequency range: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .250 Hz to 10 kHz
Bandwidth: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .± 30 Hz to ± 250 Hz
Input level range: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1 V to 3.5 Vrms
Input Impedance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200
Ω
Output Impedance: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2500
Ω
Steepness factor: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 - 15
Steepness factor is defined as: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bandwidth at 60 dB
Bandwidth at 3 dB
Voltage Insulation: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .750 VDC from input terminals to output terminals
Operating temperature: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-20°C to +50°C
Storage temperature: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to + 80°C
Note: Other frequencies, bandwidths, impedances and other characteristics are available upon request.
7443 SERIES
ISSUE: P1 23/10/02
229 Colonnade Road, Ottawa, Ontario, Canada K2E 7K3
Tel: (613) 226-1626 Fax: (613) 226-7124
www.filtran.com
An ISO 9001 Registered Company
FILTRAN [ FILTRAN LTD ]
