R V R ELETTRONICA EDL150-FM FM Transmitter User Manual
- June 13, 2024
- R V R ELETTRONICA
Table of Contents
R V R ELETTRONICA EDL150-FM FM Transmitter
Introduction
The EDL150-FM is a dummy load produced by RVR Elettronica SpA to be used with
FM transmitter with nominal power up to 150 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 EDL150-FM is particularily suited for the use in compact transmission
systems, thanks to its small form-factor. The quadratic construction enables a
simple installation.
Working Principle
Simply speaking, the EDL150-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.
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!
WARNING: don’t cover the airflow grid, to ensure proper functioning of
the device.
Power Derating
The power that the EDL150-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.
Technical characteristics
| Frequency band | 87.5 – 108.0 MHz |
|---|---|
| Nominal power at 40°C | 150 W |
| Power derating at t > 40 °C | 3 W/°C |
| Return loss | > 26 dB |
| Size | (L x H x D) 120 x 100 x 150 mm |
| Weight | 2.5 kg |
Images
This chapter contains the schematic of EDL150-FM as well as some pictures
DIAGRAM
Manufactured by 
Italy
