Ampex 300 - 300 Ccir Parts List Electronic Assembly; Model 300 Electronic Assembly; Variations in Circuitry for Ccir Equalized Electronic Assemblies

2R31
Resistor,
variable: 100 K ohm, 20%, 114 watt: Chicago Telephone
Supply Part No. UPE-70, Spec. 31186
Reproduce Board Assembly
Record Board Assembly
Harness Assembly
MODEL 300 ELECTRONIC ASSEMBLY
VARIATIONS IN CIRCUITRY FOR CCIR EQUALIZED ElECTRONIC ASSEMBLIES
FROM STANDARD NAB EQUALIZATION.
RECORD AMPLIFIER-
044-204
30962-04
30963-04
30819-03
1. An additional equalization circuit comprising of a 20 millihenry choke (1L1) and a .0025
microfarad capacitor (C109) was mounted on the terminal board.
2. Capacitor C105 (.1 microfarad) and resistor R107 (lOOK) were removed and the terminals
were shorted to ground.
REPRODUCE AMPLIFIER-
1. A 5K pot was added (R224). One terminal was connected to ground and the other terminal
connected to a normally closed circuit of K102 (a previously unused contact set). One
terminal of L101 was connected to one lead of C109. The remaining lead of C109 was
connected to the moving contact of K102. The normally closed contact of this contact set
is
connected to ground.
2. Capacitor C206 was changed to .068 microfarad. C206 lead (formerly connected to R207)
now connects to a moving contact of K102. The terminal of R207 now free, was connected
to a normally open contact of K102.
Ref. No.
R224
C109
C206
L101
300 CCiR PARTS LIST
ELECTRONIC ASSEMBLY
CATALOG NUMBER MOD. 559-00
Part Description
Resistor, variable: 5K ohms, 20%, 1/2 W: Chicago Telephone supply:
Type 65 (TRP D) LT-2
Capacitor, mica: .0025 mfd., 500V dcw, 5% : Elmenco Part No.
CM30B202M
Capacitor, paper: tubular, .068 mfd., 400 V dcw, 10%: Sprague
Part No. 88P68394S4
Coil, RF: 20 MA: Miller Part No. 691
3-2
Ampex
Catalog No.
044-073
034-076
035-134
051-018