WesternElectric-142A-pwr-sm 电路图 维修手册.pdf

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1、Amplifi ers 1 4 2 A A M P L I F I E R The 142A Amplifi er is a basic amplifi er unit with a power output of 25 watts. Its construction is such that a large variety of input combinations can be installed directly on the chassis. This permits stocking a number of basic units which can be easily modifi

2、 ed to fi t individual require m e n t s . Typical Specifi cations frequency 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 loudspeaker distribution line. See Figure 54. Gain

3、; 50 db from 600 ohm source. Gain Control; Continuously variable master control. Chassis drilled for channel controls. Output Power; As supplied for use with commercial re ceiver type tubes (6L6), 12 watts ( + 41 dbm) 50-7500 cycles with 5% total harmonic distortion. May be recon nected to use Weste

4、rn Electric 350B Tubes in the output circuit for 25 watts ( + 44 dbm) with less than 5% total harmonic distortion over the frequency range of 50-7500 cycles. Power Supply; 105 - 125 volts, 60 cycles, a-c. 185 watts maximum (1.65 amperes). Fused with thermal cutout fuse. Quantity Required 2 2 1 V A C

5、 U U M T U B E S Western Electric 3 5 0 B o r Commercial Receiver Type 6 S N 7 G T 6 L 6 5 U 4 G Mounting; Relay rack or in KS-13625 List 3 Cabinet. When amplifi er is mounted in the KS-13625 List 3 Cabinet it is coded the 1142A. For relay rack mounting a 405B Panel should be ordered. See page 95, C

6、omponents and Accessories. Dimensions; For relay rack mounting 8% x 19. Finish; Chassis light gray. 1 4 2 A - A M P L I F I E R TYPICAL FREQUENCY RESPONSE (Measured between Nominal Impedances; i . L ! Frequency In Cycles per Second Frequency Response Curve, 142A Amplifi er. 1 4 2 B A M P L I F I E R

7、 The 142B Amplifi er is a 142A basic unit plus a high gain pre-amplifi er, the 141A. It is especially adaptable for use with microphone and other low output devices. Typical Specifi cations Frequency Response; 2 db, 50 to 15,000 cycles, 1 db, 50 to 10,000 cylces. Output Noise; 5 dbm at maximum gain;

8、 25 dbm at 90 db gain. Harmonic Distortion; See Output Power. Source Impedance; 30, 250, or 600 ohms. Load Impedance; 1.5 to 36 ohms or 70-volt loudspeaker distribution line. See Figure 54. Gain; 115 db. Gain Controls; Continuously variable master and three steps of 10 db each on 141A chassis. Outpu

9、t Power; As supplied for use with commercial re ceiver type tubes (6L6), 12 watts ( + 41 dbm), 50-7500 cycles with 5% total harmonic distortion. May be recon nected to use Western Electric 3 5 OB Tubes in the output circuit for 25 watts ( + 44 dbm), with less than 5% total harmonic distortion over t

10、he frequency range 50-7500 cycles. Potver Supply; 105 - 125 volts, 60 cycles, a-c. 185 watts maximum (1.65 amperes). Fused with thermal cutout fuse. Quantity Required 3 1 2 1 V A C U U M T U B E S Western Electric 3 5 0 B o r Commercial Receiver Type 6 S N 7 G T 6J7 6 L 6 5 U 4 G Mounting; Relay rac

11、k or in KS-13625 List 3 Cabinet. When the amplifi er is mounted in the KS-13625 Cabinet it is coded the 1142B. Eor relay rack mounting a 405B Panel should be ordered. See page 95, Components and Accessories. Dimensions; Eor relay rack mounting, 8% x 19. Finish; Chassis light gray. 1 4 2 B - A M P L

12、I F I E R TYPICAL FREQUENCY RESPONSE (Measured between Nominal Impedances) Frequency in Cycles per Second Frequency Response Curve, 142B Amplifi er. 302 RadioFans.CN 收音机爱 好者资料库 142-A/142- B/142-C/142-D f 4 2 C A M P U F I C R1 4 2 D A M P L I F I E R The 142C Amplifi er is a 142A basic amplifi er un

13、it plus a line coil. It is especially suited for applications where high gain amplifi ers are not required. Typical Specifi cations Frequency 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

14、 to 36 ohms, or 70 volt loudspeaker distribution line. See Figure 54. Gain: 66 db. Gain Control: Continuously variable. Output Power: As supplied for use with commercial re ceiver type tubes (6L6), 12 watts ( + 41 dbm), 50-7500 cycles with 5% total harmonic distortion. May be recon nected to use Wes

15、tern Electric 3 5 OB Tubes in the output circuit for 25 watts ( + 44 dbm), with less than 5% total harmonic distortion over the frequency range of 50-7500 cycles. Power Supply: 105 - 125 volts, 60 cycles, a-c. 185 watts maximum (1.65 amperes). Fused with thermal cutout fuse. Quantity Required V A C

16、U U M T U B E S Western Electric Commercial Receiver Type 6 S N 7 G T 6 L 6 5 U 4 G Mounting: Relay rack or in KS-13625 List 3 Cabinet. When amplifi er is mounted in the KS-13625 List 3 Cabinet it is coded the 1142C. For relay rack mounting a 405B Panel should be ordered. See page 95, Components and

17、 Accessories. Dimensions: For relay rack mounting, x 19. Finish: Chassis light gray. The 142D is a basic 142A Amplifi er unit plus a l4lA pre-amplifi er and a line coil. The two input circuits, one of which may be used with a microphone, provide a fl ex ible combination of mixing and control, for pr

18、actically all sound systems. Typical Specifi cations Frequency Response: Microphone Input: 2db, 50-15,000 cycles; 1 db, 50-10,000 cycles. Line Input: 1.5 db, 50-10,000 cycles. Output Noise: Microphone Input at maximum gain: 5 dbm. Microphone Input at 90 db gain: 25 dbm. Line Input: 30 dbm. Harmonic

19、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 loudspeaker distribution line. See Figure 54. Gain Control: Continuously variable master and an addi tional three step control, 10 db each

20、step, on l4lA Pre amplifi er. Output Power: As supplied for use with commercial re ceiver type tubes (6L6), 12 watts (+41 dbm), 50-7500 cycles with 5% total harmonic distortion. May be recon nected to use Western Electric 3 5 OB Tubes in the output circuit for 25 watts ( + 44 dbm), with less than 5%

21、 total harmonic distortion over the frequency range of 50-7500 cycles. Power Supply: 105 - 125 volts, 60 cycles, a-c. 185 watts maximum (1.65 amperes). Fused with thermal cutout fuse. Quantity Required 1 3 2 1 V A C U U M T U B E S Western Electric Commercial Receiver Type 6J7 6 S N 7 G T 6 L 6 5 U 4 G Mounting: KS-13625 List 4 Cabinet. When amplifi er is mounted in this cabinet it is coded the 1142D. Finish: Chassis- ight gray. 3 0 3 RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库