G.R.A.S. 26AH 1/2'' SysCheck Preamplifier with 3 m integrated cable

Freq range: 2.5 Hz - 200 kHz Noise: 1.8 µV Gain: -0.35 dB Special feature: SysCheck

Typical application & use

Precision measurements

Low-pressure measurements

General-purpose preamplifiers

Design

All G.R.A.S. microphone preamplifiers are based on a small ceramic thick-film substrate with a very high input impedance. The ceramic substrate is shielded by a guard ring to minimise the influence of stray capacitance and microphonic interference. The casing is made of stainless steel for maximum strength and durability. The small dimensions of the 26AH ensures reliable operation under humid conditions owing to the heat generated by internal power dissipation.

G.R.A.S. 26AJ has SysCheck for easy remote verification of the measurement chain. It allows you to send a test signal to an RC network in the preamplifier. This signal is applied to pin 1 of the 7-pin LEMO cable/connector. SysCheck does not result in a signal proportional to the microphone’s sensitivity, but it gives you a way to determine whether your system is stable. SysCheck cannot replace a proper acoustic calibration of the microphone.

 

Compatibility

The  preamplifier is compatible with ½-inch microphones as defined in international standard IEC1094 Measurement Microphones, Part 4: Specifications for working standard microphones. The mounting thread (11.7 mm - 60 UNS-2) is compatible with other available makes of similar microphone preamplifiers.

Preamplifier Type 26AH is provided with a 3 m high-quality cable terminating with a 7-pinLEMO series 1B plug.

Frequency range (±0.2 dB) with 18 pF microphone dummy Hz 2.5 to 200 k
Slew rate V/µs 20
Input impedance GΩ // pF 20 // 0.4
Output impedance Ω 75
Output Voltage Swing, max. @ ±14V/+28V power supply Vp 12
Output Voltage Swing, max. @ ±60V/+120V power supply Vp 50
Noise (A-Weighted) max. µV 2.5
Noise (A-Weighted) typ. µV 1.8
Noise (Linear 20 Hz – 20 kHz) max. µV 6
Noise (Linear 20 Hz – 20 kHz) typ. µV 3.5
Gain dB -0.35
Power supply, single V 28 to 120
Power supply, balanced V ±14 to ±60
DC-offset, min., single suppy V 0.5 x Vs - 1
DC-offset, max., single suppy V 0.5 x Vs + 4
DC-offset, balanced supply V -1 to 4
Temperature range, operation °C / °F -30 to 70 / -22 to 158
Temperature range, storage °C / °F -40 to 85 / -40 to 185
Humidity range non condensing % RH 0 to 95
Connector type 7-pin LEMO (FGG.1B.307)
CE/RoHS compliant/WEEE registered Yes / Yes, Yes
Weight g / oz 32.0 / 1.13
Conditions: 23 °C Ambient temperature, ±60V/+120V power supply, 18 pF dummy microphone, 3 m output cable.
G.R.A.S. AA0008 3 m extension cable (7-pin1B LEMO)
G.R.A.S. AA0009 10 m extension cable (7-pin1B LEMO)
G.R.A.S. AA0012 30 m extension cable (7-pin1B LEMO)
G.R.A.S. AA0014 100 m extension cable (7-pin1B LEMO)
G.R.A.S. RA0017 1-inch to ½-inch adaptor for use with G.R.A.S. 1-inch microphones
G.R.A.S. RA0019 ¼-inch to ½-inch adaptor for use withG.R.A.S. ¼-inch microphones