Cobalt C-50

Add to quote

Quick Enquiry Form

Want to know more about this product? 



Perfect for low-power applications like smaller Transmitter sites, use as an Exciter or as a Gap-filler, Sporting where low power, and High quality audio are needed.

The COBALT C-50 Transmitter has a superior audio quality and sound clarity thanks to it‘s Direct to Channel Digital technology.

Running on a fully customised LINUX OS system, this low distortion modulator is available on all models within the COBALT family of FM Transmitters. Inputs and outputs include Analog, AES/EBU, Digital MPX (AES192), Ethernet, USB, GPIO, GPS Sync with built in SFN capabilities.

The modern design lets you easily read the Ultra-clear RGB display, and the intuitive Joystick controls with Haptic feedback and additional silicon buttons allows fast setup, getting you on the air even faster.

The advanced communication package with Intuitive web interface and remote control via Ethernet (https) lets you make changes or monitor the COBALT Transmitter. Full SNMP Version 3 management and the ability to send emails, alerts and monitor audio remotely gives you added confidence knowing you have full control from anywhere in the world on any device with a Web browser.

Easy access to all components and software controlled variable fan speed, will guarantee you low cost of maintenance . The highest AC efficiency, a compact design and reduced weight mean low cost of transportation and far the lowest total cost of ownership in it‘s class.


  • Dynamic, UECP Compliant RDS Encoder
  • Direct to Digital Synthesized modulation
  • Digital MPX with MPX power Limiter
  • 4 Band Audio Processing
  • Linux OS
  • RGB Screen
  • Ethernet Control and SNMP
  • GPS Sync
  • Optional Auxiliary DC power input

Technical Specifications:


Output Power (W) 50
Range (W) 0.1-50
RF Output connector N-Type (Female)
Input ACV @ 50/60Hz 100-240 (277 North America only)
Power Connector IEC 13A filtered
Power consumption ~125W @ max power
AC-RF efficiency typ ~40%
Temperature controlled fan 1
Power supplies 1
Dimensions WxDxH (cm) 48.3 x 38 x 4.45 (1RU)
Weight 3.7kg


Transmitter type Solid-state FM Stereo transmitter
Modulator Direct-to-channel (DDS)
RF Output Frequency Range VHF Band II, 87-108MHz
RF Frequency Steps 50/100kHz
Frequency Stability ±1 ppm with internal 10MHz clock reference
FM Modulation Range Capability 75kHz default, 100% modulation adjustable up to 250kHz


Power Stability ≤ ± 0.25dB
Asynchronous/AM noise ≤ -60dB
Synchronous AM s/n ratio ≤ -60dB
RF Harmonic and Spurious Suppression Meets ETSI requirements
VSWR operation Fully protected against gradual or sudden VSWR conditions.
Proportional power reduction from VSWR 1.5:1

Stereo Encoder

Modes Stereo, Mono L+R, Mono L, Mono R
Frequency response 20Hz – 15kHz
Pre-emphasis 0, 50 or 75µs
Pilot tone 19kHz, adjustable level
Subcarriers suppression ≤ -70dB
Stereo separation >80dB digital, >70dB analogue
SNR >85dB
THD+N <0.03%

Audio Inputs

Analogue 2 x XLR female, 10kΩ impedance, level from 0dBu up to 24dBu
Digital AES/EBU via RJ45 per StudioHUB+, level from -24dBFS up to 0dBFS, sampling rates 32-192kHz

RDS Generator

Type Fully Dynamic RDS/RDS2/RBDS Generator
Protocols ASCII commands, UECP protocol and X-Command
Ports Multi-port architecture: UART over USB-B & Ethernet

Communication & Control

10MHz input BNC, 50Ω terminated
1PPS input BNC, 50Ω terminated
RF sample output SMA, 50Ω, -30dBc
UART over USB USB-B, system control
USB 2 x USB-A, storage & FW upgrade
Ethernet 2 x RJ45, 1x System controller, 1x AES67 compatible IP audio
RS232 DB25 shared connector, system control
GPIO DB25 shared connector, 8 x output & 8 x input, all optically isolated.
Interlock/RF Mute DB25 shared connector