McIntosh MR 74, Owner'S Manual, Page: 11 / 20

PERFORMANCE GUARANTEE — Performance limits
are the maximum deviation from perfection permitted
for a Mclntosh instrument. We promise you that the
MR 74 you buy must be capable of performance at or
exceeding these limits or you get your money back.
Mclntosh is the only manufacturer that makes this
guarantee.
FM SECTION
TUNING RANGE: 88 to 108 MHz
ANTENNA INPUTS: 300 ohms balanced; 75 ohms
unbalanced
INTERMEDIATE FREQUENCY (IF): 10.7 MHz
SENSITIVITY: 2.5 µV at 100% modulation (± kHz
deviation) for 3% total noise and harmonic dis-
tortion
SIGNAL TO NOISE RATIO: 70 dB below 100% mod-
ulation
HARMONIC DISTORTION: MONO — 0.3% at 100%
modu 75 kHz deviation; STEREO — 0.5%
at 100% modulation
DRIFT: 25,000 Hz for the first two minutes; there-
after 5,000 Hz at 25°C in 24 hours
FREQUENCY RESPONSE: ± 1 dB 20 Hz to 15,000 Hz
with standard de-emphasis (75 µ sec.)
CAPTURE RATIO: 1.5 dB minimum
SELECTIVITY:
Switch Setting NORMAL NARROW
Adjacent Channel: 6 dB 15 dB
Alternate Channel: 68 dB 88 dB
SPURIOUS REJECTION: 90 dB
IMAGE REJECTION: 95 dB; 88 to 108 MHz (IHF)
MUTING: 50 dB noise reduction in LOCAL position
MUTING THRESHOLD: DISTANT position 3 µ V ; LO-
CAL position 10 µV
SCA FILTER: 50 dB down from 67 kHz; 275 dB per
octave slope
STEREO SEPARATION: 35 dB at 1,000 Hz
STEREO FILTER: 10 dB noise reduction in Position 1
20 dB noise reduction in Position 2
AM SECTION
SENSITIVITY: 75 µV (external ant.)
SIGNAL TO NOISE RATIO: 55 dB at 100% modula-
tion; 45 dB minimum
HARMONIC DISTORTION: 1% at 30% modulation
SELECTIVITY, ADJACENT CHANNEL: 35 dB in
NORMAL position; 45 dB in NARROW position
IMAGE REJECTION: 65 dB 540 kHz to 1600 kHz
FREQUENCY RESPONSE: SELECTIVITY SWITCH IN
NORMAL position 3500 Hz, 6 dB down
NARROW position 2100 Hz, 6 dB down
All tuner performance limits were measured with se-
lectivity switch set at normal; unless otherwise stated
GENERAL
AUDIO OUTPUT: front panel controlled: 2.5 volts into
47,000 ohms. Fixed Output: 2.5 volts into 47,000
ohms; 1.0 volt into 600 ohms
POWER REQUIREMENTS: 120 volts, 50/60 Hz, 30
watts
SEMICONDUCTOR COMPLEMENT: 5 FETs, 17 tran-
sistors, 2 ICs, 30 diodes, 1 indicator tube
MECHANICAL INFORMATION
SIZE: Front panel: 16 inches wide (40.64 cm) by
5-7/16 inches high (13.81 cm); Chassis: 15 inches
wide (38.1 cm) by 13 inches deep (33.02 cm), in-
cluding PANLOC shelf and back panel connectors;
Knob clearance: 1½ inches (3.81 cm) in front of
mounting panel
WEIGHT: 25 pounds (11.34 kg) net; 37 pounds (16.78
kg) in shipping carton
FINISH: Front Panel: Anodized gold and black with
special gold/teal panel nomenclature illumination;
Chassis: Chrome and black
MOUNTING: Mclntosh developed professional PAN-
LOC
9
Performance Limits