Table Of Contents - Racal Instruments TRA 7928 Technical Manual

Table of Contents

First Aid In Case Of Electric Shock2
Product View9
General Information11
Specifications12
Additional Items List14
Installation15
Location Of Fuses15
Simple End Fed Aerial Arrangement16
Fixed Site Station17
Power17
Aerial17
Earthing17
Mobile Mounting Arrangement18
Mobile Installation19
Vehicle Mounting19
Mobile Aerial Mounting20
Marine Installation22
Operation25
Controls25
Indicator Lamp26
Press-To-Talk (Ptt)26
Principles Of Operation31
Reception (Usb Operation)31
Transmission (Usb Operation)32
Am Operation33
Switchable Sideband33
Emergency Calling33
Supply Lines And Switching Circuits35
Receive And Transmit 9V Lines/12V Line35
Receive Am Line35
Usb/Lsb Operation35
Oven Oscillator Unit39
Channel Oscillator39
Carrier Insertion Oscillator39
Oven Control Circuit40
Oven Oscillator Unit Type 304743
Exciter Receiver Board Type 302845
Filter Switch47
If Trap47
First Mixer47
Sideband Filter47
If Amplifiers48
Second Mixer48
Audio Pre-Amplifier48
Agc48
Exciter Circuit49
Af Output Amplifier49
Af Amplifier49
Rceive And Transmit Supporting Circuitry50
If Strip50
10Mhz Low Pass Filter50
First Mixer Drive50
Alternative Operating Modes51
Second Mixer Drive51
9V Regulator51
Am Filter Switching51
Switchable Sideband Operation52
Limiting Amplifier52
Secondary Detector52
Ci - Re-Insertion/Af Oscillator52
Power Amplifier Type 301953
Ac Signal Path55
Dc Bias55
Alc Peak Output Detecting And Limiting56
Average Output Detecting (Am Operation)56
Aerial Tuning Indicator56
Two Tone Generator Board Type 418657
Aerial Tuning Unit Type 303259
Tuning Circuit59
Reflectometer Type 450959
Recommended Test Equipment61
Dismantling And Re-Assembly63
Chassis Layout64
Removal Of Exciter/Receiver Board Type 302865
Removal Of Power Amplifier 301965
Separation Of Heat Sink And Board66
Removal Of Oven Oscillator Unit67
Removal Of Channel Oscillator Crystals67
Removal Of Carrier Insertion Oscillator Crystal67
Removal Of Two Tone Generator Board Type 418668
Removal Of Aerial Tuning Unit68
Removal Of Items Mounted To Front Panel68
Overall Transceiver Tra 7928 Checks69
Dc Supply Check71
Location Of Faulty Module72
Receiver Functional, Transmitter Not73
Tansceiver Non Functional On One Channel73
Transceiver Non Functional On Any Channel74
Tests On Oven Oscillator Unit Type 304475
Input/Output Dc Voltages77
Oven Beating And Control77
Tests On Oven Oscillator Unit Type 304779
Oven Heating And Control81
Tests On Exciter/Receiver Board 302885
Dc Check85
Ac Checks86
Tests On Power Amplifier 301989
Tests On Power Amplifier Type 301991
Typical Voltages Measured With Respect To -Ve Rail93
Typical Voltages Measured With Respect To +Ve Rail94
Tests On Two Tone Generator Board Type 418695
Tests On Aerial Tuning Unit Type 303297
Reflectometer Board Typical Voltages97
Alignment Procedures99
Oven Oscillator Units101
Oven Temperature Adjustments101
Channel Oscillator Adjustment102
Initial Transmitter Alignment103
Sideband Filter Adjustment103
Am Filter Alignment104
Post Filter Alignment104
Carrier Re-Insertion Alignment104
Receiver Initial Settings105
Receiver Not Fitted With Am Facility105
Receiver Fitted With Am Facility105
If Rejection105
Diagrams And Parts Lists109