Performance Limits
PERFORMANCE GUARANTEE - Performance limits
are the maximum deviation from perfection permitted
for a Mclntosh instrument. We promise you that the
MR 78 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.
TUNING RANGE: 88 to 108 MHz
ANTENNA INPUTS: 300 ohms balanced; 75 ohms
unbalanced
INTERMEDIATE FREQUENCY (IF): 10.7 MHz
SENSITIVITY: 2µV for 35 dB of quieting; 2.5µV at
100% modulation (±75 KHz deviation) for 3% total
noise and harmonic distortion.
SIGNAL TO NOISE RATIO: 75 dB below 100% modu-
lation.
HARMONIC DISTORTION: 0.2% mono or stereo at
100% modulation to 15,000 Hz. Typically, 0.05% at
1,000 Hz
DRIFT: 25,000 Hz for the first two minutes; thereafter
5,000 Hz at 25°C in 24 hours.
FREQUENCY RESPONSE: MONO - ±1 dB 20 Hz to
20,000 Hz with standard de-emphasis, (75µS);
STEREO - ±1 dB 20 Hz to 15,000 Hz with standard
de-emphasis <75µS)
CAPTURE RATIO: 0.25 dB detector only; 2.5 dB com-
plete tuner
SELECTIVITY: IHF
SELECTIVITY SWITCH SETTING
SUPER
NORMAL NARROW NARROW
Adjacent Channel 7 dB 22dB 55dB
Alternate Channel 55dB 80dB 80dB
SUPURIOUS REJECTION: 100 dB IHF
IMAGE REJECTION: 100 dB, 88 to 108 MHz. IHF
INTERMODULATION DISTORTION: 0.2% mono or
stereo for any combination of frequencies from 20 Hz
to 15,000 Hz with peak modulation equal to 100% or
less. Typically 0.1%
9
MAXIMUM SIGNAL INPUT: 12 volts across 300
ohm antenna terminals will not increase harmonic
or intermodulation distortion
AUDIO HUM: 70 dB down from 100% modulation
MUTING: 70 dB noise reduction between stations
MUTING THRESHOLD (Typical): Distant position
5µV; Local position 20µV
SCA FILTER: 50 dB down from 67 KHz to 74 kHz;
275 dB per octave slope
STEREO SEPARATION: 40 dB at 1,000 Hz
STEREO FILTER (Typical): 10 dB noise reduction in
Position 1.
20 dB noise reduction in Position 2.
AUDIO OUTPUT: Front Panel Controlled: 2.5 volts
into47,000 ohms.
Fixed Output: 2.5 volts into 47,000 ohms; 1.0 volt
into 600 ohms.
All tuner performance limits were measured with
SELECTIVITY switch set at NORMAL, unless otherwise
stated.
GENERAL INFORMATION
POWER REQUIREMENT: 120 volts, 50/60 Hz 35 watts
SEMICONDUCTOR COMPLEMENT: 3 JFET's, 2
MOSFET's, 17 Bipolar Transistors, 43 Diodes, 4 Inte-
grated Circuits
MECHANICAL INFORMATION
SIZE: Front Panel: 16 inches wide (40.65 cm) by5-7/16
inches high (13.8 cm); Chassis: 15 inches wide (38.1
cm) by 13 inches deep (33.1 cm), including PANLOC
shelf and back panel connectors; Knob clearance"
1-1/2 inches (3.85 cm) in front of mounting panel.
WEIGHT: 27 pounds (12.25 kg) net, 39 pounds (17.69
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
