Signal Generator
SG62
Instruction Manual
ADVANCE COMPONENTS LIMITED
INSTRUMENT DIVISION
ROEBUCK ROAD, HAINULT, ILFORD, ESSEX, ENGLAND
TELEPHONE: HAINULT 4444 TELEGRAMS: ATTENUATE ILFORD
Publication 135
Contents
Section 1 Introduction 4
Section 2 Specification 5
Section 3 Operation 7
3.1 Supply Voltage 7
3.2 Frequency Selection 7
3.3 R.F. Output 7
3.4 Output Termination 7
3.5 Modulation and CW 7
3.6 Audio Frequency Output 7
3.7 Connections to Points of High Potential 8
Section 4 Maintenance 9
4.1 Removal of Instrument Case 9
4.2 Replacement of Instrument Case 9
4.3 Valve Replacement 9
Section 5 Components List 10
Section 6 Factory Service 13
Illustration
Fig. 1 Circuit Diagram 12
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1
1. Introduction
The Wide Band Signal Generator SG62 provides r.f. signals over the frequency range 150 kc/s to 220 Mc/s, thus covering most radio and television bands. The instrument employs a Colpitts oscillator with six ranges that are displayed on a calibrated dial having a total length of 50 inches. A band spreading device maintains an open scale at the high frequency end of each range.
An overall frequency accuracy of ± 1% is achieved and an adjustable cursor provides means of obtaining greater accuracy when checked against standard frequencies, such as a broadcast carrier signal or crystal calibrator.
The output signal is available as a continuous sine wave or may be amplitude modulated 30% at 400 c/s, when an audio frequency signal is also available at separate terminals. The output level is controlled by an accurate attenuator system which permits repeatable measurements with signal levels as low as 1µV.
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2
2 Specification
Frequency Ranges 150 kc/s – 500 kc/s
500 kc/s – 1.m Mc/s
1.8 Mc/s – 6 Mc/s
6 Mc/s – 20 Mc/s
20 Mc/s – 70 Mc/s
70 Mc/s – 220 Mc/s
Accuracy ± 1% with cursor in central position.
R/F. Output The output is fed through a 75Ω cable, which should be terminated either by termination unit, type TP2B, or any other load of 75Ω. The voltage into the terminating load is adjustable from 1µV to 100 mV by means of a five position attenuator and a continuously variable control.
Accuracy of maximum output ±3db.
Accuracy of step attenuator ± (3db+3 µV).
Output Impedance The output impedance at the end of the output cable is 75Ω when it is not terminated, except at the x10mV position of the step attenuator when it varies from 60 to 85Ω. When terminated the impedance becomes 37.5Ω.
Modulation The r.f. signal is available as either a continuous wave or midulated 30% ± 3db at 400 c/s ±10%.
Audio Frequency An audio frequency signal of 400 c/s at approximately 10V is available into a high impedance when the oscillator is modulated.
Valves and 1 Valve type 12AT7
Accessories 1 Neon Pilot Lamp, 100-125V.
1 75Ω Termination Pad type TP2B.
1 Connector Cable R.F. , type PL28.
Power Supply The standard model is operated from power supplies of 105- 125V, 140-160V, 210-250V, 40-100c/s. Consumption approximately 20W.
Weight 10 lb (4.5kg).
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Dimensions 12 in. X 9 in. X 6 in. (30.5 cm, X 22.9 cm, X 15.2 cm).
Finish Dark blue metal case complete with leather carrying handle.. Light grey front panel with medium grey surround. Knobs medium grey. Colours to B.S. 2660. Case tint No. 7-086, front panel tint No. 9-093, front panel surround tint No. 9-095.
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