WesternElectric-142A-pwr-sm 维修电路原理图.pdf

Amplifiers1 4 2 A A M P L I F I E RThe 142A Amplifier is a basic amplifier unit with apower output of 25 watts. Its construction is such that alarge variety of input combinations can be installed directlyon the chassis. This permits stocking a number of basicunits which can be easily modified to fit individual requirem e n t s .Typical Specificationsfrequency Response; 1 db, 50 to 15,000 cycles.Output Noise; 30 dbm.Harmonic Distortion; See Output Power.Source Impedance; 0250,000 ohms.Load Impedance; 1.5 to 36 ohms or 70 volt loudspeakerdistribution line. See Figure 54.Gain; 50 db from 600 ohm source.Gain Control; Continuously variable master control. Chassisdrilled for channel controls.Output Power; As supplied for use with commercial receiver type tubes (6L6), 12 watts ( + 41 dbm) 50-7500cycles with 5% total harmonic distortion. May be reconnected to use Western Electric 350B Tubes in the outputcircuit for 25 watts ( + 44 dbm) with less than 5% totalharmonic distortion over the frequency range of 50-7500cycles.Power Supply; 105 - 125 volts, 60 cycles, a-c. 185 wattsmaximum (1.65 amperes). Fused with thermal cutout fuse.Quantity Required221V A C U U M T U B E SWestern Electric3 5 0 B o rCommercialReceiver Type6 S N 7 G T6 L 65 U 4 GMounting; Relay rack or in KS-13625 List 3 Cabinet.When amplifier is mounted in the KS-13625 List 3 Cabinetit is coded the 1142A. For relay rack mounting a 405BPanel should be ordered. See page 95, Components andAccessories.Dimensions; For relay rack mounting 8% x 19.Finish; Chassis light gray.1 4 2 A - A M P L I F I E RTYPICAL FREQUENCY RESPONSE(Measured between Nominal Impedances;i . L!Frequency In Cycles per SecondFrequency Response Curve, 142A Amplifier.1 4 2 B A M P L I F I E RThe 142B Amplifier is a 142A basic unit plus a highgain pre-amplifier, the 141A. It is especially adaptable foruse with microphone and other low output devices.Typical SpecificationsFrequency Response; 2 db, 50 to 15,000 cycles, 1 db,50 to 10,000 cylces.Output Noise; 5 dbm at maximum gain; 25 dbm at90 db gain.Harmonic Distortion; See Output Power.Source Impedance; 30, 250, or 600 ohms.Load Impedance; 1.5 to 36 ohms or 70-volt loudspeakerdistribution line. See Figure 54.Gain; 115 db.Gain Controls; Continuously variable master and threesteps of 10 db each on 141A chassis.Output Power; As supplied for use with commercial receiver type tubes (6L6), 12 watts ( + 41 dbm), 50-7500cycles with 5% total harmonic distortion. May be reconnected to use Western Electric 3 5 OB Tubes in the outputcircuit for 25 watts ( + 44 dbm), with less than 5% totalharmonic distortion over the frequency range 50-7500cycles.Potver Supply; 105 - 125 volts, 60 cycles, a-c. 185 wattsmaximum (1.65 amperes). Fused with thermal cutout fuse.Quantity Required3121V A C U U M T U B E SWestern Electric3 5 0 B o rCommercialReceiver Type6 S N 7 G T6J76 L 65 U 4 GMounting; Relay rack or in KS-13625 List 3 Cabinet.When the amplifier is mounted in the KS-13625 Cabinetit is coded the 1142B. Eor relay rack mounting a 405BPanel should be ordered. See page 95, Components andAccessories.Dimensions; Eor relay rack mounting, 8% x 19.Finish; Chassis light gray.1 4 2 B - A M P L I F I E RTYPICAL FREQUENCY RESPONSE(Measured between Nominal Impedances)Frequency in Cycles per SecondFrequency Response Curve, 142B Amplifier.302RadioFans.CN 收音机爱 好者资料库142-A/142- B/142-C/142-Df 4 2 C A M P U F I C R1 4 2 D A M P L I F I E RThe 142C Amplifier is a 142A basic amplifier unit plusa line coil. It is especially suited for applications wherehigh gain amplifiers are not required.Typical SpecificationsFrequency Response: 1.5 db, 50-10,000 cycles.Output Noise: 30 dbm.Harmonic Distortion: See Output Power.Source Impedance: 37.5, 150, or 600 ohms.Load Impedance: 1.5 to 36 ohms, or 70 volt loudspeakerdistribution line. See Figure 54.Gain: 66 db.Gain Control: Continuously variable.Output Power: As supplied for use with commercial receiver type tubes (6L6), 12 watts ( + 41 dbm), 50-7500cycles with 5% total harmonic distortion. May be reconnected to use Western Electric 3 5 OB Tubes in the outputcircuit for 25 watts ( + 44 dbm), with less than 5% totalharmonic distortion over the frequency range of 50-7500cycles.Power Supply: 105 - 125 volts, 60 cycles, a-c. 185 wattsmaximum (1.65 amperes). Fused with thermal cutout fuse.Quantity RequiredV A C U U M T U B E SWestern ElectricCommercialReceiver Type6 S N 7 G T6 L 65 U 4 GMounting: Relay rack or in KS-13625 List 3 Cabinet.When amplifier is mounted in the KS-13625 List 3 Cabinetit is coded the 1142C. For relay rack mounting a 405BPanel should be ordered. See page 95, Components andAccessories.Dimensions: For relay rack mounting, x 19.Finish: Chassis light gray.The 142D is a basic 142A Amplifier unit plus a l4lApre-amplifier and a line coil. The two input circuits, oneof which may be used with a microphone, provide a flexible combination of mixing and control, for practically allsound systems.Typical SpecificationsFrequency Response: Microphone Input: 2db, 50-15,000cycles; 1 db, 50-10,000 cycles. Line Input: 1.5 db,50-10,000 cycles.Output Noise: Microphone Input at maximum gain: 5dbm. Microphone Input at 90 db gain: 25 dbm. LineInput: 30 dbm.Harmonic Distortion: See Output Power.Source Impedance: Microphone Input: 30, 250, 600 ohms.Line Input: 37.5, 150, 600 ohms.Load Impedance: 1.5 to 36 ohms, or 70 volt loudspeakerdistribution line. See Figure 54.Gain Control: Continuously variable master and an additional three step control, 10 db each step, on l4lA Preamplifier.Output Power: As supplied for use with commercial receiver type tubes (6L6), 12 watts (+41 dbm), 50-7500cycles with 5% total harmonic distortion. May be reconnected to use Western Electric 3 5 OB Tubes in the outputcircuit for 25 watts ( + 44 dbm), with less than 5% totalharmonic distortion over the frequency range of 50-7500cycles.Power Supply: 105 - 125 volts, 60 cycles, a-c. 185 wattsmaximum (1.65 amperes). Fused with thermal cutout fuse.Quantity Required1321V A C U U M T U B E SWestern ElectricCommercialReceiver Type6J76 S N 7 G T6 L 65 U 4 GMounting: KS-13625 List 4 Cabinet. When amplifier ismounted in this cabinet it is coded the 1142D.Finish: Chassis-ight gray.3 0 3RadioFans.CN 收音机爱 好者资料库