HAND-HELD CARBON MICROPHONE
GENERAL
The Shure Model 104C is a small, pressure–actuated, dia-
phragm–type, carbon microphone specially designed for
clear, efficient speech reproduction. The 104C fits naturally
and comfortably in the hand, and retains this feel in hot or
cold weather. The sturdy, high–impact ARMO–DUR
case
is light and compact, and occupies minimal space in portable
or mobile equipment.
The 104C is equipped with a heavy-duty, push-to-talk
switch and a long life, rubber-jacketed coil cord cable.
Features:
•
Frequency response from 300 to 4,000 Hz, specifically
designed for voice communications use
•
Small, light and compact case, takes minimum space in
portable and mobile equipment, fits comfortably and
firmly in the hand
•
Extremely rugged, high-impact ARMO-DUR
case,
stronger and lighter than die-cast metal, comfortable to
the touch in hot or cold weather
•
Double-pole, single-throw, leaf-type switch designed to
stand up under rigorous operating conditions and
constant usage
•
Long life, rubber-jacketed coil cord
•
Rugged and dependable under all operating conditions
APPLICATIONS
The Model 104C is especially recommended for all types
of outdoor and indoor communication activity: in mobile and
fixed station use (as in police, fire, utility, forestry and trans-
portation services), and in commercial and industrial ap-
plications—including radiotelephone, amateur radio and
similar uses. The microphone is also suitable for voice ap-
plications in indoor and outdoor public address.
The Model 104C will operate satisfactorily under most
conditions of temperature and humidity.
The Model 104C is a replacement for Shure Model 101C,
101E, 102C, 102E, 104A and 1048 Carbon Microphones.
INSTALLATION AND CONNECTIONS
A mounting bracket for permanent installation is sup–
plied with the Model 104C (see Figure 1).
46 mm
36.5 mm
4.7 mm
34.5 mm
10.3 mm
9.5 mm
9.1 mm
(23/64 IN.)
(3/8 IN.)
(1-13/16 IN.)
(1-7/16 IN.)
(3/16 IN.)
(1-23/64 IN.)
(13/32 IN.)
MOUNTING HOLES,
CLEARANCE FOR
No. 8 SCREWS
MOUNTING BRACKET
FIGURE 1
The internal switch connections of the Model 104C are
shown in Figure 2. The Model 104C has a double-pole,
single-throw, normally open, leaf-type switch to control the
microphone and relay or switching circuits.
The Model 104C has a four-conductor coiled-cord cable:
The RED and BLACK leads are the microphone circuit, and
the GREEN and WHITE leads are for connection to the relay
or switching circuit.
A typical operating circuit using the Model 104C is shown
in Figure 3. The voltages (E) and corresponding resistances
required to limit the operating current through the carbon
cartridge to approximately 50 mA are as follows:
E (Volts)
Total Minimum Circuit
Resistance (ohms)
4.5
50
6
100
12
200
24
500
Note that the resistance value includes both resistance R
in the figure plus other dc circuit resistance (transformer pri-
mary, etc.). The Model 104C will operate satisfactorily with
current up to 50 mA. However, no damage will result if the
current rises to 100 mA. The resistance of the carbon car-
tridge is 30 ohms with 50 mA flowing through the cartridge.
Model 104C Guide
27B1149 (AC)
2001, Shure Incorporated
Printed in Mexico
