Chapter 1 G EN ER A L IN FO RM A T IO N 1 . 1 Introduction . . . , . , 1. 2 Data summary 1 .3 Versions and a c c e sso r ie s Chapter 2 O P ERA T IO N 2.1 P relim in a ry requirements 2.2 ^ AC supply cable __________ 2.3 “ Battery operation 2.4 Fuses . . . . . . 2.5 Controls and connectors 2.6 Setting frequency ________ 2.7 СW output . . . . . . 2.8 Internal amplitude modulation 2.9 Internal frequency modulation 2.10 External a.m. or f .m . . . . 2.11 Internal a .m . with external f.m. 2.12 Internal f .m. with external a .m . 2.13 Internal modulation output 2.14 Operation with digital S3rnchronizer 2.15 Sweep facility . . . . . . 2.16 Attenuator calibration . . . 2.17 Matching to high impedance loads 2.18 Use of i . f Probe 2.19 Quieting sensitivity measurements 2.20 Correct use of the -H3cLB output facility Decibel conversion tables . . . 10 10 10 10 10 12 13 13 13 13 13 13 14 14 14 14 14 15 16 15 16 & 17' chapter 3 T EC H N IC A L DESCRIPTION 3.1 Mechanical characteristics ... . . . ___ ... 19 3.2 Overall function . . . . . . . . . . . . . . . ... 19 3.3 Circuit functions ... . . . . . . ... 20 3.4 R F Oscillator 20 3.5 Tuning and frequency modulation . . . . . . . . . ... 20 3.6 F ir s t a . i . c . loop . . . . . . . . . . . . . . . ... 20 3.7 Pre Amplifier 20 3.8 Modulator and amplitude modulation . . . . . . ... 21 3.9 Counter Amplifier 21 3.10 AM driver and d .c . offset circuits . . . . . . ... 21 3.11 Wide band Amplifier 21 3.12 Second a . I .e . circuit . . . . . . — — ... 21 3.13 Fine r . f. output control . . . . . . . . . . . . ... 21 3.14 Modulation Oscillator 22 3.15 Predistortion circuit . . . . . . . . . . . . ... 22 3.16 +6 dB output . . . . . . . . . . . . . . . ... 22 3.17 Monitor circuits . . . . . . . . . . . . . . . ... 23 3.18 Coarse r . f . output control . . . . . . . . . . . . ... 23 3.19 Power unit . . . . . . . . . . . . . . . . . . ... 23 3.20 Supply Filter 23 Chapter 4 M A IN T EN A N C E 4.1 Introduction __ ___ 4 . 2 Sc r ew f a s t e n e r s . . . . . . . . . 4 . 3 Access to sub-nssomblies and components 4.4 P relimin a ry checks ... 4.5 Test equipment . . . . . . . . . 4.6 Performance chccks . . . . . . 4. 6.1 Power Supply Unit A20 4.6.2 Frequency calibration Unit Δ12 (sub-assemblies A l 4.G.3 R F output (normal) 4.6.4 R F output (+6 dB) . . . 4.6.5 Checking v . s .w . r . (frequencies 350 to 500 MHz) 4.6.6 Checking v . s .w . r . (frequencies 10 to 350 MHz) 4.6.7 Modulation Oscillator performance 4.6.8 Checking f .m . deviation 4.6.9 Checking a .m . depth 4.6.10 Checking f .m . tracking 4 . 6 . 1 1 Checking a . I . e . s y s t em 4.6.12 Counter output level 4.6.13 External modulation sensitivity 4.6.14 AM distortion . . . 4.0.15 FM distortion . . . 4.6.16 üpurious f .m . on c .w . 4.6.17 Spurious a ,m . on c .w . 4.6.18 Spurious a .m , on f .m . 4.6.19 Spurious f .m . on a .m . 4.6.20 C a r r ie r harmonics 4.6.21 Coarse r . f . output control 4.6.22 Fine r . f . output control 4.7 Cleaning rotary switches . . . to A l l ) 24 2 1 21 24 2 1 27 27 23 28 2 Я 28 29 29 29 30 30 30 30 30 31 31 31 32 32 33 33 33 33 33 Chapter 5 REPAIR 5.1 Introduction . . . __ __ ___ 5.2 Fault location . . . . . . . . . 5. 3 Replacing tuning drive cord . . . 5.4 Replacing transformers A16, T I , T2 5.5 Additional information . . . 34 34 39 40 40 Chapter 6 REPLA CEA BL E PARTS Introduction and ordering Index to units 41 54 Chapter 7 C IRC U IT DIAGRAMS Circuit notes . . . . . . F ig . 7.1 R F o s c i l l a t o r s . . . . . . 7.2 Wide band Amplifier modulator - a 7.3 Tuning - modulation - monitor circuits 7.4 Power unit and coarse attenuator .c . circuits