R.V.R. Elettronica EDL600-FM User manual

EDL600-FM
User manual
Manufactured by Italy

EDL600-FM
iInstruction Manual Rev. 1.2 - 08/03/07
Table of Contents
1. Introduction 1
2. Working Principle 1
3. External Description 1
4. Power Derating 2
5. Tec nical specifications 3
6. Images 3

EDL600-FM
1 / 6Instruction manual Rev. 1.2 - 08/03/07
1. Introduction
The EDL600-FM is a dummy load produced by RVR Elettronica SpA to be used
with FM transmitter with nominal power up to 600 W
Dummy loads are mainly used as laboratory test devices and are often included in
redundant (1+1 or N+1) transmission systems, in which the output of the spare
transmitter is normally connected to the dummy load for test pourpouses
The EDL600-FM is particularily suited for the use in compact transmission systems,
thanks to its small form-factor The quadratic construction enables a simple installation
2. Working Principle
Simply speaking, the EDL600-FM is just a 50 Ω resistive load, optimized to work in
the audio FM band
The applied power is dissipated by four 50 Ω power resistors connected in a series/
parallel configuration (see the enclosed schematic), able to compensate the parasitic
capacitance of the resistors, to obtain a return loss better than 26 dB on the whole
87 5 - 108 MHz band
The resistors are fixed on a metal heatsink, and three fans generate the air flow to let
the heat pass to the environment
The fans are activated by a thermal bimetallic switch, that is normally opened and will
close as soon as the heatsinks temperature surpasses 55 °C
!
WARNING: Always connect the power source (the transmitter) using the interlock
connectors, to avoid the possibility of an excessive temperature rise that could
damage the dummy load and even the transmitter itself!
3. External Description
The following drawing shows the dummy load
!
WARNING: dont cover the airflow grid, to ensure proper functioning of the device

EDL600-FM
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Abbildung 1: Hintere Tafel
[1] Interlock connectors BNC with inner normally grounded, floating in case of interlock
[2] Input RF connector RF (N-type)
[3] VDE plug for mains supply (220 AC)
[4] Mains fuses for the fans (1A RAPID)
4. Power Derating
The power that the EDL600-FM can continuosly dissipate depends on the temperature
of the environment
Since the dummy load can work at a temperature up to 90 °C before the protection
device is triggered, figure 2 gives the acceptable working area of the device
!
WARNING: Please remember that it is essential to link the transmitter to the interlock
connectors of the EDL600-FM, to avoid the risk of damaging it
10 20 30 40 50 60 70 80
200
400
600
800
:DWW
&
7HPSHUDWXU
Illustration 2: Admitted function-types

EDL600-FM
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5. Tec nical c aracteristics
Frequency band 87.5 - 108.0 MHz
Nominal power at 0°C 600 W
Power derating at t > 0 °C 12 W/°C
Return loss > 26 dB
Power Supply 230V ac + / - 10%
Fuse 2 A
Size (L x H x D) 320 x 85 x 375 mm
Weight 12 kg
6. Images

EDL600-FM
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EDL600-FM
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EDL600-FM
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