B&K 2627 Instructions And Applications page 11

Fig.2.2. The Preamplifier Type 2627, with and without the 8 & K 1 inch
microphone, and 7 pin plug (dimensions in mm)
Thread for Microphone
Polarization
Voltage
Ground
(Heating element)
Signal
Casing to outer screen
Looking at pins from outside
120 V DC Supply
Heating element
Fig.2.3. Pin connection of output plug
The preamplifier connects directly to the PREAMP. INPUT of most of
the B & K Measuring Amplifiers, Frequency Spectrometers, and the Real
Time Analyzer. The preamplifier input socket on these instruments delivers
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