Polar Pattern
Unidirectional (cardioid), uniform with frequency,
symmetrical about axis (see Figure 2)
TYPICAL POLAR PATTERN
FIGURE 2
Output Impedance
Rated at 150 ohms (90 ohms actual)
Recommended minimum load impedance: 800 ohms
(May be used with loads as low as 150 ohms with
reduced clipping level)
Output Level
(at 1,000 Hz)
Open Circuit Voltage . . . . . . . . . . . . . -80.0 dB (0.10 mV)
0 dB = 1V/µbar
Preamplifier Output Clipping Level
(at 1,000 Hz, less than
0.1% THD)
800 ohm load . . . . . . . . . . . . . . . . . . . . . . . . . 0 dBV (1.0V)
150 ohm load . . . . . . . . . . . . . . . . . . . . . . -13 dBV (0.22V)
Maximum SPL
(at 1,000 Hz)
800 ohm load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 dB
150 ohm load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 dB
Hum Pickup
-5 dB equivalent SPL in 1 m0e field (60 Hz)
Output Noise
34 dB SPL, A-weighted
37 dB SPL, weighted per DIN 45 405
Signal-to-Noise Ratio
64 dB re 94 dB SPL
Dynamic Range
121 dB
Phasing
Positive pressure on diaphragm produces positive
voltage on pin 2 relative to pin 3 of preamplifier output
connector
Power
Battery: Two 9-Vdc alkaline (NEMA 1604A), approxi-
mately 300 hours continuous with fresh alkaline
batteries
Simplex (Phantom) Voltage: 11 to 52 Vdc, operational
down to 9 Vdc; 1.8 mA current drain; permissible to use
simplex power with batteries in place or removed
Switches and indicator
Two recessed slide switches and green LED indicator
on top surface of preamplifier assembly
Battery On/Off Switch:
Move to On to power from bat-
teries or to use batteries as backup power in case of
interruption to external power supply (no battery drain
occurs as long as simplex voltage source is greater than
battery voltage). Move to Off to prevent battery drain
when unit is not in use
LED Indicator:
Green LED flashes momentarily when
switch is moved to On to indicate at least 8 hours of
battery life remaining
Flat/Lo Cut Switch:
In Lo Cut position, 12 dB/octave
rolloff below 80 Hz (see Figure 1)
Cable
4.6m (15 ft) two-conductor shielded, small diameter,
interconnecting cable with 3-socket miniature Switch-
craft Tini Q.G. connector on each end to mate with
microphone output connector and preamplifier input
connector
Case
Microphone: Matte black enamel brass case and stain-
less steel inner grille
Preamplifier: Matte black enamel die-casting
Dimensions
See Figure 3
OVERALL DIMENSIONS
FIGURE 3
Environmental Conditions
Operating Temperature:
-18° to 57° C (0° to 135° F)
Storage Temperature:
-29° to 74° C (-20° to 168° F)
Relative Humidity (Operating or Storage):
0 to 95%
Net Weight
Microphone: 12 grams (0.4 oz) less cable
Preamplifier: 435 grams (15.4 oz) less batteries
Furnished Accessories
Windscreen, Swivel Adapter
USING THE SWIVEL ADAPTER
To mount the SM98 in the supplied swivel adapter:
1. Mount the adapter on a microphone stand.
2. Loosen the thumbscrew at the top of the adapter.
3. Attach the microphone to the connector.
4. Slip the cable through the slot in the adapter. Slide the
connector back through the hole until the protruding
black cable-lock button is in the open slot and the
microphone stops flush with the flat on the adapter.
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