Motorola SLR5500 DMR Repeater 50W 1U Rackmount

The Motorola SLR5500 is a 1U rackmount DMR repeater rated 1 to 50 W adjustable, at a 100% duty cycle across the full output. It is the compact end of the MOTOTRBO infrastructure line, and its case for selection is density rather than raw power: 44 x 483 x 370 mm and 8.6 kg, against the far larger and heavier MTR3000. Where a shelter, a cabinet or a comms room has limited rack space, or a site needs several repeaters rather than one big one, that difference decides the design.

What the Motorola SLR5500 delivers

It supports MOTOTRBO single-site conventional, IP Site Connect, Capacity Plus, Linked Capacity Plus and Connect Plus, plus analogue conventional and MPT 1327, and it will run mixed analogue and digital. It holds 64 channels and covers VHF 136-174 MHz and UHF 403-470 MHz. Channel spacing is 12.5, 20 or 25 kHz, the 25 kHz option being unavailable in the United States, which matters only if equipment is being specified to a common global standard across regions.

A 100% duty cycle at continuous full 50 W output is the specification that separates infrastructure from a mobile radio pressed into repeater duty. This is a station designed to transmit all day at rated power without stepping down, which is what a busy site actually asks of a repeater during a shift change or an incident.

Installation and site engineering

Antenna connections are a BNC-female receive port and an N-female transmit port, so cable assemblies should be specified accordingly rather than assumed. Input voltage is 100-240 Vac at 47-63 Hz, which suits Saudi mains without a step transformer. A built-in 3 A battery charger and an auxiliary power output mean backup can be built around the station itself instead of adding a separate charging shelf, a real saving where cabinet space is the constraint.

The operating range of -30 C to +60 C is the specification that matters for unconditioned sites: a rooftop plant room or a remote cabinet in the Eastern Province can be planned around it. That said, ambient rating is not a substitute for airflow, and a station running continuously at 50 W in a sealed enclosure still needs a ventilation plan.

Sixty-four channels give a mid-sized frequency plan room to breathe with spare capacity for expansion, and mixed-mode support lets analogue and digital channels run on the same station during a migration, so a site does not need a separate repeater per technology while handsets are replaced in stages.

Management and lifecycle

Built-in 100/1000Base-T Ethernet carries remote diagnostics, monitoring and software updates, so routine attention does not require a site visit, while a front-panel USB port handles local configuration. There is no display: front-panel status LEDs report state, which is the normal arrangement for equipment that lives in a rack and is managed over the network.

The power amplifier, power supply and modem are field-replaceable modules, and the chassis has provision for expansion modules, so a fault becomes a module swap and a capability change does not necessarily mean a new station. Reliability has been validated through Motorola’s Accelerated Life Testing programme. Warranty is two years as standard and extendable under Service from the Start.

Choosing the SLR5500 over the MTR3000

Choose this repeater when the site needs VHF or UHF coverage in minimal rack space, when several repeaters will be distributed rather than concentrated, or when weight and cabinet depth are constrained. Step up to the MTR3000 where the requirement is higher transmit power, the additional spectrum that station covers, base-station operation in analogue mode, or an integrated battery-revert supply. Both run the same MOTOTRBO system types, so fleet features are not the deciding factor. Installation in Saudi Arabia requires the appropriate regulatory licence for the frequencies and site in use.

Package Contents

• SLR5500 repeater
• 230 V AC power cable
• rack-mount brackets