Introduction To Type 5998; Front Panel - BRUEL & KJAER 5998 Service Manual

Chapter 1 — General Information

Introduction to Type 5998

1.5 Introduction to Type 5998
The electronics of Type 5998 are mains powered and built into a robust casing
which has two microphone channels, one of which is used for the transmitter and
the other for the receiver. The instrument also includes a high-precision 200 V po-
larization voltage supply. The polarization voltage can be checked using the exter-
nal digital voltmeter, and adjusted to the correct level using a front-panel
adjustment. As an alternative, an external polarization voltage can be applied. See
the block diagram in
Each channel has built-in relays to allow external control of the apparatus via its
IEEE – 488 interface bus and selection of the required measurement configurations.
This allows PC control of an automatic sequence to measure the transmitter/receiv-
er electrical transfer impedance at all selected frequencies
1.5.1

Front Panel

This section details the functions of the controls, connectors and indicators on the
front panel.
Channel A:
Channel B:
Gain:
1 − 4
section 5.3
Receiver: 7-pin LEMO socket for connection of the signal from the re-
ceiver microphone. Pin connections are shown in Fig.1.3.
Polarization Voltage: 3-position sliding switch for selection of 0 V,
+200 V microphone polarization voltage or an external polarization volt-
age.
Overload: Red LED which lights when there is an overload (> 10 V
on channel A.
Transmitter: 7-pin LEMO socket for connection of the signal to/from
the transmitter microphone. Pin connections are shown in Fig.1.3.
Polarization Voltage: 3-position sliding switch for selection of 0 V,
+200 V microphone polarization voltage or an external polarization volt-
age.
Overload: Red LED which lights when there is an overload (> 10 V
on channel B.
Ref. Adj.: ± 10 dB potentiometer for adjusting the level of the reference
signal. The level can be measured using the Ref. Signal Output socket
on the back panel of the apparatus.
Two pushkeys for increasing or decreasing the gain applied to a signal
(both channels). Range: 0 – 50 dB in 10 dB steps. The setting is indicat-
ed by one of the green LEDs above the pushkeys.
Reciprocity Calibration Apparatus Type 5998
Service Manual
for more details.
)
peak
)
peak
Brüel & Kjær