MT-MR PLATINUM. POINT TO POINT AURAL RADIO RELAY SYSTEM
20
Each transmitter/receiver couple has its oscillator and RF circuits designed for 20 MHz sub-bands tuning within
each frequency band selected. Customer must take care in choosing the type of antennas adequate for the
selected frequency band. OMB has some models of good-performance Yagis for all allowable link frequency bands
into the MT-MR Platinum system's working range.
System can operate connected to 110-120 vAC or 220-240 vAC Mains sources. Both MT Platinum transmitter and
MR Platinum receiver has incorporated a sturdy heavy-duty switching Power Supply in order to withstand AC
voltage fluctuations, keeping the overall system reliability in a high-level value.
There are plenty of metering facilities both at transmitter and receiver. Digital Display of MT Platinum allows to
supervise transmitted and reflected power levels, and also equipment's carrier frequency deviation. Pilot LEDs also
supervise the oscillator's PLL frequency lock, normal operation of the Switching Power Supply and normal RF
output selected. In the other hand, MR Platinum multimeter allows to supervise both received RF signal strength
and incoming carrier modulation level.
Also, MR Platinum receiver has a pilot LED indicating local oscillator's PLL frequency lock, and another LED
indicating the presence of a normal received signal level. There also exists some monitoring facilities like a
headphones connection and audio level control, and a small monitoring speaker to locally check received audio
quality. To avoid unpleasant noise to be reproduced by receiver's audio amplifier circuits in event of any abnormal
behavior like a fading or an AC failure at transmitter station, MR Platinum receiver also has incorporated a mute or
squelch circuit to cut out the audio output signal when signal-to-noise ratio of incoming signal lowers to some pre-
determined mute threshold level. This muting circuit can be set on or off from a switch located at Receiver's front
panel.
All cable connectors are located at rear panels, both at system's transmitter and receiver. This fact contributes to a
better organization and neat appearance of the racks where equipments are mounted. We recommend to install
both transmitter and receiver in standard 19" normalized closed cabinets, both to keep this presence at its best
level, and to preserve equipment from dust and dirtiness.
Concerning this aspect, both equipments will be installed in environments that are free from dust and dirtiness, and
only under climatic conditions prescribed in their correspondent Technical Specifications. We recommend the use
of air- conditioned rooms where it's possible. Otherwise, equipments' room must has a ventilating and de-humidifier
system in order to keep the system operating under stable and safe climatic conditions. Under local conditions
involving the possibility of severe AC failures, it is advisable to select the DC feeding for both Transmitter and
Receiver, if necessary. Both equipments are delivered to Customer fitted with DC mains supply requirements. This
DC supply will have + 15 vDC, negative to ground. Under severe AC failure conditions, it will be better to adquire
this option, and connect equipment/s to a 15 vDC Battery rack, this battery being in turn connected to a DC Battery
Charger to keep battery always charging under "floating" conditions.
NO INTERNAL ADJUSTMENT OR PRESETTING IS REQUIRED DURING NORMAL
OPERATION. EQUIPMENTS SHALL BE PROPERLY GROUNDED AND BE
OPERATED WITH ALL THE COVERS CLOSED TO PREVENT ELECTRICAL
HAZARDS AND COMPLY WITH EMC STANDARDS.
OMB hence recommends for these equipments not to be handled by unskilled personnel, together with antenna
system, transmission lines and the remaining components, both at Transmitter & Receiver heads and related
equipments and station's antennas system. A good installation, made by skilled and trained personnel will avoid
many future troubles during system's exploitation process.
