Endevco® model EM26CF
½-inch microphone preamplifier with gain and filters
Feartures / applications
Description
• 0 dB and +20 dB gain settings
• Linear, A-weighting and high-pass filter (20 Hz) settings
• Isotron® inputs
• Prepolarized microphones
• ½-inch precision microphones
• High levels and high frequencies
The Endevco ½-inch preamplifier model EM26CF is a
general purpose preamplifier optimized for use with
prepolarized condenser microphones. It is a small, robust
unit and uses an Endevco Isotron® power supply, eg. model
4416B. It has low inherent noise level, a large dynamic range
and a frequency response from 2.5 Hz to 100 kHz.
Gain and filter switch settings
There are two flush-mounted switches for selecting various
combinations of gain and filtering, i.e.:
Gain switch settings:
0 dB - for normal microphone signals.
+20 dB - for boosting weak microphone signals.
Filter switch settings:
A-weighting - as required in standard measurements.
Linear - to let the microphone signal pass unfiltered.
High-pass - to cut off unwanted low frequencies.
The frequency responses of the A-weighting filter is shown
in Fig.1.
Its small ceramic thick-film substrate has a very high input
impedance, and is shielded by a guard ring to minimize the
influence of stray capacitance and microphonic interference.
The model EM26CF can be used with all Endevco
prepolarized microphones, namely:
• ½-inch microphones:
Models EM40AE, EM40AD and EM40AQ
• ¼-inch microphones:
Models EM40BE and EM40BD, using the optional
½-inch to ¼-inch adaptor
It has an integrated BNC output connector.
The casing is made of stainless steel for maximum strength
and durability.
Endevco® model EM26CF
½-inch microphone preamplifier
with gain and filters
Specifications
Frequency response (cable load 4.7 nF):
2.5 Hz–100 kHz
Input impedance:
Output impedance (Cs = 20 pF, f = 1000Hz):
Noise (measured with 20 pF ½-inch dummy mic.):
Linear, 0 dB:
Linear, 20 dB:
A-weighted, 0 dB:
High pass, 0 dB:
A-weighting filter:
High-pass filter:
Gain:
Typically:
Power-supply:
Maximum signal-output voltage (peak):
Temperature:
Operation:
Storage:
Relative humidity:
Operation:
Storage:
Connector type:
Dimensions and weight:
Diameter:
Length:
Weight:
±0.2 dB
(typical for 0 dB gain and linear setting)
20 G Ω, 0.4 pF
< 50 Ω
typically 8 µV rms
typically 65 µV rms
typically 10 µV rms
typically 10 µV rms
Compliant with IEC 61672-1 Class 1
3-pole butterworth, –3 dB at 20 Hz
-0.25 dB
4 mA to 20 mA (typically 4 mA)
±5.0 V
-30°C to +70°C (-22°F to 158°F)
-40°C to +85°C (-40°F to 185°F)
0 to 95%
0 to 95%
BNC
12.7 mm (½-inch)
92 mm (3.6 inches)
30 g (1 oz)
Accessories
Product
Description
EM42AA
Pistonphone
Optional
4416B
Isotron power supply
Optional
133
Signal conditioner
Optional
EM40AE
½” condenser microphone
Optional
EM40AD
½” condenser microphone
Optional
EM40AQ
½” condenser microphone
Optional
EM40AO
½” condenser microphone
Optional
EW967
RG58C coaxial cable, BNC male/male, 4 ft
Optional
EW968
RG58C coaxial cable, BNC male/male, 6 ft
Optional
Fig.1 Frequency resonse of A-weighting lter shown graphically (compliant with IEC 61672-1 Class 1)
Continued product improvement necessitates that Meggitt reserve the right to modify these specifications without notice. Meggitt maintains a program of constant surveillance over
all products to ensure a high level of reliability. This program includes attention to reliability factors during product design, the support of stringent Quality Control requirements,
and compulsory corrective action procedures. These measures, together with conservative specifications have made the name Endevco synonymous with reliability.
APPLIES TO CALIFORNIA FACILITY
©Meggitt (San Juan Capistrano), Inc. All Rights Reserved 30700 Rancho Viejo Road, San Juan Capistrano, CA 92675 USA
(800) 982-6732 • (949) 493-8181 fax (949) 661-7231 • www.endevco.com • Email: applications@endevco.com 040512