Maximum reliability

Reliabiliy by design

Civilian design philosophies improve reliability of military communications

Rohde & Schwarz considered several factors before designing its new high-power transmitter:

• Avoid and minimize single points of failure at a transmit station
• Reduce transmitter downtime for maintenance and repair
• Consider emergency scenarios and contingencies relevant to communications equipment.

Running costs are another important factor that are not given enough consideration in military equipment. However, recurring costs are a major factor in civilian designs for broadcasting equipment, where availability is very important. Interrupting a transmission can have a direct financial impact on an operator in the form of lost advertising revenue.

Proven components used in demanding commercial applications

The innovative cooling system of the HF high-power transmitters offer multiple benefits for maximum availability.

Rohde & Schwarz placed a new liquid-cooled high-performance amplifier at the heart of the R&SR®SK41xx HF high-power transmitter. Each transmitter has a self-sufficient liquid cooling system to absorb the enormous amount of waste heat and transport it from the building. The transmitter building no longer needs a forced dry air circulation system to cool the transmitter or dissipate waste heat from the transmitter room, eliminating the points of failure in forced dry air generation or air conditioning systems. It also reduces the thermal load for the entire transmitter with precise cooling of the amplifier modules. The closed-loop cooling system protects high-power transmitters from harsh environmental conditions such as wet, corrosive coastal air, extending the transmitter life, while reducing maintenance, repair and overhaul downtime for better HF transmitter station reliability and lower costs.

Liquid cooling has low energy consumption relative to conventional forced air cooling or air conditioning systems and the HF transmitters only need emergency power to operate, further reducing costs. Uninterruptible power supplies (UPS) are also available for HF transmitters to prevent short-term voltage failures or voltage fluctuations when switching from normal to emergency power and keep the transmitter control online. It also helps avoid time-consuming restarts after power outages.

Remote monitoring and error analysis are possible with the R&SR®SK41xx high-power transmitter. The transmitter components are designed with inbuilt redundancy. Even if a power supply or power amplifier is faulty, the transmitter will operate at reduced power until the next scheduled maintenance session or a replacement is brought to the transmitter station.

Emergency operations

In emergency operation, the R&SR®SK41xx achieves the following power outputs:

• 30% of system output power if one final stage is defective
• 80% of system output power if one power supply is defective

Proven technologies and concepts from civilian broadcasting helped Rhode & Schwarz develop high-performance HF transmitters with outstanding reliability. This results from:

• Eliminating two single points of failure in the transmitter station
  
  • No forced dry air cooling or air conditioning systems for the transmitter
• Being able to cool the transmitter even in emergency power mode
• Reducing downtimes for maintenance and repair
  
  • Minimizing the thermal loads for HF high power transmitters means longer intervals between maintenance and lower failure rates
  • Longer maintenance intervals for self-sufficient cooling
  • The cooling system can be serviced while the transmitter is operating
• Reducing downtime from unreliable or unstable power supplies
  
  • Optional UPS for transmitter control prevents time-consuming restarts
  • Reducing down-time with remote monitoring and error analysis
  • Emergency operations with reduced HF transmit power due to redundant design

The exacting quality standards at Rohde & Schwarz and this approach to cooling make for much more reliable military communications.