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ET120 & ET60 

Induction Loop Amplifiers 

 

 

 

 

 

Installation and Maintenance Manual 

 

Revision 1A − August 2005 

 

Please Read Carefully Before Commencing 

Installation 

 

 

 

 

Summary of Contents for ET120

Page 1: ...ET120 ET60 Induction Loop Amplifiers Installation and Maintenance Manual Revision 1A August 2005 Please Read Carefully Before Commencing Installation ...

Page 2: ... any other signals When microphones are to be used it is vital that they are positioned to pick up sound which is free from reverberation and other noises If the microphones receive a poor signal then the signal transmitted to the listener will be poor no matter how good the design of the loop and other equipment It is also necessary to ensure that the microphones are matched electrically to the a...

Page 3: ... Mic Sets the Level of the Microphone inputs Line Sets the level of the Line inputs Metal loss correction to restore the high frequencies in areas containing large quantities of metal Drive Sets the output current from the loop amplifier Important Safety Information This Equipment must only be installed and maintained by suitably skilled and competent person This Equipment is defined as Class 1 in...

Page 4: ...d box will also guard them against mechanical damage Unpacking the Unit Remove the Unity DAU from its packing and check the contents against the following list 1 AFILS amplifier Unit 2 Installation maintenance manual this document 3 2 5mm AF Alan Key Using the HEX key supplied remove the front cover Verify the following items are present 1 1 off 3 way Microphone Screw terminal block 2 1 off 4 way ...

Page 5: ...used knockouts must be left unopened to comply with the LVD Low Voltage Directive accidentally knocked out holes should be blanked off This work must be carried out prior to the re installation of circuit boards Mounting The Amplifier Before mounting the AFILS amplifier on the wall it is advisable to remove the cable knockouts as described above The ET120 weighs 3KGs so care should be taken to sec...

Page 6: ... angled connecting plug Balanced Microphone The balanced microphone input is presented on a three way two part screw terminal connection and is designed to accept the microphone cables directly The input provides a balanced 12V phantom supply to power electret type microphones such as the ETCM W and works with most professional microphones unbalanced dynamic microphones should not be used with loo...

Page 7: ...om the table below the maximum impedance of the loop cable should be 3Ω when measured using an impedance or LCR meter at 1KHz Maximum length m Vs Cable Size mm2 Amplifier 1 1 5 2 5 4 0 ETCF ET60 70 80 90 100 90 ET120 90 105 120 140 140 ETCF copper foil tape is equivalent to 1 8mm2 cable but has a lower inductance per metre Commissioning Before powering up the amplifier check all mains wiring and s...

Page 8: ...nputs Audio inputs 1 off balanced mic or unbalanced mic 1 off 100V line or balanced line selectable Type 2 part 5mm Screw terminals Line Power Aux 12V 100mA for loop OK signs and input pre amplifiers Phantom 12V 2mA Sensitivity 50dBV Microphone 40dBV 100V line 10dBV balanced line Mains Input Voltage 230V 50 60 Hz Current 250mA Nominal 180mA Power 90VA Max 60VA Max Internal fuses Mains 1A F HBC Fus...

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