|Racal Dana 9478 Frequency Standard|
|Description||Frequency Standard Distribution System|
The Racal-Dana Frequency Standard Distribution System 9478 provides a reliable and convenient means of generating and distributing up to nine standard frequency signals, all phase locked to a single Frequency Standard. Where more than nine independent outputs are required, two or more systems may be cascaded. FREQUENCY STANDARD The Frequency Standard used may be internally mounted. A choice of two crystal oscillators from the Racal-Dana range is offered. The specifications of these oscillators are given in Section 1. Alternatively an external master Oscillator or atomic Frequency Standard may be used. External frequency standards having outputs at 1 MHz, 2 MHz, 2.5 MHz, 5 MHz or 10 MHz are all suitable for use with the 9478. Systems fitted with an internal Frequency Standard will automatically lock to the input from an external standard when such an input is present. SYSTEM OUTPUTS The nine BNC output sockets are mounted on the rear panel. Each is fed from' an individual driver Amplifier and provides a level of 1 V r.m.s. into 50 ft. Internal coaxial links, which may easily be reset by the user, allow the frequency at any output to be set to 1 MHz, 5 MHz, or 10 MHz. STATUS INDICATORS Each output channel is provided with an individual LED indicator. These are mounted on the front panel, and light when an output is present. In addition a TTL compatible, logic '1' alarm signal is given at a rear panel mounted connector if any output fails. Two further front panel LED indicators are provided. One lights when the system is in lock, and the other when an input from an external Frequency Standard is present. Both indicators are repeated, in the form of TTL compatible logic '1' levels, at a rear panel mounted connector.
These manuals are available for the above equipment:
|Racal Dana -- 9478 -- Service and User Manual|
|Manual Type||Service and User Manual|
|Size||3.72 Mbytes (3897857 Bytes)|
|Date||01 November 1982|
|Quality||Scanned document, all readable.|
|Upload date||03 February 2018|
|Downloads||0 since 03 February 2018|
1. TECHNICAL SPECIFICATION 1-1 1.1 Specification 1-1 2. GENERAL DESCRIPTION 2-1 2.1 Introduction 2-1 2.2 Frequency Standard 2-1 2.3 System Outputs 2-1 2.4 Status Indicators 2-1 2.5 Maintenance 2-1 3. PREPARATION FOR USE 3-1 3.1 Power Supply 3-1 3.1.1 AC Voltage Range Setting 3-1 3.1.2 Line Fuse 3-1 3.1.3 Power Lead 3-2 3.2 Fitting the Fixed Rack Mounting Kit 11-1496 3-2 3.3 Setting the Output Channel Frequencies 3-3 3.4 External Status Indicator Connection 3-4 3.5 Connection of External Frequency Standard 3-5 3.6 Cascade Connection 3-5 3.7 Removal and Replacement of Covers 3-5 4. OPERATING INSTRUCTIONS 4-1 4.1 Introduction 4-1 4.2 Description of Controls, Indicators and Connections 4-1 4.2.2 Front Panel Items 4-1 4.2.3 Rear Panel Items 4-1 4.3 Switching On 4-2 4.4 Switching Off 4-2 5. PRINCIPLES OF OPERATION 5-1 5.1 Introduction 5-1 5.2 Principle of Operation 5-1 5.3 Technical Description 5-1 5.3.1 External Standard Input Circuit 5-1 5.3.2 External Standard Detector 5-3 5.3.3 Internal Standard Input Circuit 5-3 5.3.4 Internal Standard Detector 5-3 5.3.5 Phase Detector Drive Circuit 5-3 5.3.6 Loop Oscillator 5-4 5.3.7 Phase Detector Operation 5-4 5.3.8 The Loop Filter 5-5 5.3.9 Lock Indicator Circuit 5-5 5.3.10 Loop Outputs 5-5 5.3.11 Output Driver Amplifiers 5-6 5.3.12 Power Supplies 5-6 6. MAINTENANCE 6-1 6.1 Introduction 6-1 6.2 Calibration Procedure 6-1 6.2.1 Test Equipment Required 6-1 6.2.2 Power Supply Tests 6-1 6.2.3 Loop Lock Setting 6-3 6.2.4 Output Level and Frequency Test 6-4 6.2.5 Spectral Purity Tests 6-4 6.2.6 Hum Sideband Test 6-6 6.2.7 Indicator and Monitor Output Test 6-7 6.2.8 Internal Frequency Standard Adjustment 6-8 7. PARTS LIST AND CIRCUIT DIAGRAMS Parts List: Front and Rear Panel Assemblies Parts List 1 Parts List: Frequency Distribution Board 19-1105 Parts List 3 Component Layout: Frequency Distribution Board 19-1105 Fig. 1 Circuit Diagram: Frequency Distribution Board 19-1105 Part 1 Fig. 2 Circuit Diagram: Frequency Distribution Board 19-1105 Part 2 Fig. 3
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