AMERICAN BOSCH MAGNETO CORP.

Complete Circuit Diagram of the Bosch Model 58 Receiver

Model 58 Receiver

L1 - 1st RF Coil
L2 - 1st RF Coil
L3 - 2nd RF Coil (untuned)
L4 - 3rd RF Coil
L5 - 3rd RF Coil
L6 - Detector Coil
L7 - Detector Plate Choke
L8 - Filter Choke

T1 - Main Power Transformer
T2 - Audio Input Transformer
T3 - Audio Output Transformer

C1 - 1st RF Tuning Condenser
C2 - 1st RF Tuning Condenser
C3 - 3rd RF Tuning Condenser
C4 - 3rd RF Tuning Condenser
C5 - Detector Tuning Condenser
C6 - Antenna Trimming Condenser
C7 - 1st RF Alignment Condenser
C8 - 3rd RF Alignment Condenser
C9 - 3rd RF Alignment Condenser
C10 - Detector Alignment Condenser
C11 - 1st RF Coupling Condenser .04 mfd.
C12 - Cathode By-pass Condenser.5 mfd.
C13 - Plate By-pass Condenser .5 mfd.
C14 - Filter Condenser .2 mfd. (25 cycle only)
C15 - 3rd RF Coupling Condenser .04 mfd.
C16 - Cathode By-pass Condenser .5 mfd.
C17 - Screen By-pass Condenser .5 mfd.
C18 - Detector Cathode By-pass Condenser 1. mfd.
C19 - Detector Screen By-pass Condenser .5 mfd.
C20 - Tone Control Condenser .006 mfd.
C21 - Detector Condenser .04 mfd.
C22 - Detector Plate By-pass Condenser .0001 mfd.
C23 - Detector Plate By-pass Condenser .0001 mfd.
C24 - Audio Coupling Condenser .006 mfd.
C25 - Power Pack Filter Condenser 2 mfd.
C26 - Power Pack Filter Condenser 2 mfd.
C27 - Buffer Condenser 1 mfd.
C28 - Audio By-pass Condenser 4 mfd.

R1 - Antenna Resistor 500 ohms
R2 - De-coupling Resistor 1,000 ohms
R3 - Screen Resistor 20,000 ohms
R4 - Volume Control 3,000 ohms
R5 - Screen Resistor 250 ohms
R6 - Untuned Transformer Resistor .1 megohm
R7 - 3rd RF de-coupling Resistor 1,000 ohms
R8 - 3rd RF Cathode Resistor 1,000 ohms
R9 - Detector Grid Resistor 1,000 ohms
R10 - Detector Cathode Resistor 50,000 ohms
R11 - Detector Screen Resistor 1 megohm
R12 - Detector Plate Resistor .25 megohm
R13 - 1st Audio Grid Resistor 2 megohms
R14 - Center Tap Resistor (chassis)
R15 - Center Tap Resistor (power pack)
R16 - Screen Supply Resistor 2,050 ohms
R17 - Audio Cathode Resistor 1,950 ohms
R18 - Divider Resistor 180 ohms
R19 - Audio Bias Resistor 950 ohms
R20 - Tone Control .5 megohm

Line Voltage 115 - Voltage Tap 115
Volume Control Full On
*Not true readings due to resistors in circuit.