McIntosh MR 71 - McIntosh MR 71 Back Panel Features; Back Panel Adjustments and Test Points; Back Panel Audio Outputs; Back Panel Antenna Connections

ITEM
NO.
USE
MR 71 PARTS LIST
TUBES
IDENTIFICATION
NUMBER
VI
RF Amplifier 1
6DS4
V2
RF Amplifier 2; Mixer
12AT7
V3
Oscillator
6BN4A
V4
IF Amplifier 1
6AU6
V5
IF Amplifier 2
6AU6
V6
IF Amplifier 3
6AU6
V7
IF Amplifier 4; Limiter 1
6AU6
V8
IF Amplifier 5 , Limiter 2; Muting
6CS6
V9
Multipath Indicator
6HU6/EM87
V10
Muting Amplifier; Muting Detector; A&C Clamp
6BN8
VI 1
Left Audio Amplifier
6BL8
VI 2
Right Audio Amplifier
6BL8
VI 3
Voltage Reference Diode
ST2-27S
VI4
MPX Amplifier, MPX Indicator Control
6U8
VI 5
MPX Oscillator
12AU7
Q1
TRANSISTOR
MPX Indicator Lamp Switch
2N3053
Dl, D2
DIODES
Selenium Rectifiers, High Voltage Power Supply
GE#6RS20PH6RGD1
D3
Variable Capacitance
Amprex S-254
D4, D5
Narrow Band Discriminator (Matched Pair)
Type 1N542 Germanium
Diode
D6, D7 Wide Band Discriminator (Matched Pair)
Type 1N542 Germanium
Diode
D8, D9
Balanced Detector for MPX Indicator (Matched Pair)
Type 1N542 Germanium
Diode
DIO, Dl 2 Balanced MPX Detectors—Left Channel (Matched Pair)
Type 1N542 Germanium
Diode
Dll, Dl3 Balanced MPX Detectors—Right Channel (Matched Pair)
Type 1N542 Germanium
Diode
Dl 4
Low Voltage Rectifier Type INI 21 7 Silicon Diode
ITEM
NO.
CONTROLS
FUNCTION RESISTANCE
IDENTIFICATION
NUMBER
R1
Automatic Freq.
Control
500K
R147 A103
R2
Muting Adj. Pot.
10K
R50, 000-6F
R3 MPX Light Adj. IK Wirt #807
R4
Volume Control
20K (Dual)
R105-164
R5
Rear Panel Output Adj. Control
40K (Dual) R147-A102
SWITCHES
ITEM
IDENTIFICATION
NO.
FUNCTION DESCRIPTION
NUMBER
SI
Muting
3 position
S147-B130
S2
Mode Selector
3 position with
S147-B105
on/off switch
S3
Panel Light Dim- Bright
SPST Stackpole SS-26
TRANSFORMERS
ITEM
IDENTIFICATION
NO. FUNCTION
NUMBER
T1 FM first IF
T107-134A
T2
FM second IF
T107-133A
T3
FM third IF T107-133A
T4
FM fourth IF T107-133A
T5
FM fifth IF, Discriminator
T107-135B
T6
FM Discriminator
T107-I35B
T7
19KC Amplifier
T129-101A
T8
38KC Oscillator
T129-102A
T9 Baiun
T10
Power
T123-133A
CAPACITORS
ITEM
IDENTIFICATION
NO.
DESCRIPTION
CAPACITANCE
VOLTAGE TOLERANCE NUMBER
Cl
Variable FM
C147-C101
C2
Antenna Trimmer
1 - 8 pf
NPO
C3
RF Trimmer 1 -8pf
NPO
C4
Mixer Trimmer 1 -8pf
NPO
C5
Oscillator Trimmer 1 -8pf
C6
Ceramic Disc lOpf
20% NPO
C7
Ceramic Disc
6.8pf 20% NPO
CIO
Ceramic Feed Thru
lOOOpf
Cl 2
Ceramic Tubular
5pf
±.25pf N330
C14
Ceramic Tubular
3pf ±.25pf NPO
Cl 5
Ceramic Tubular
1,5pf
±.25pf NPO
Cl 6
Ceramic Feed Thru
lOOOpf
Cl 8
Phenolic .18pf
10%
C19
Phenolic 3.9pf 10%
C20
Ceramic Feed Thru
lOOOpf
C22
Ceramic Feed Thru
lOOOpf
9