Radar jammers have a tell and it would be the plumbing. The three unglamorous truths of high-power electronic warfare (EW) systems are the amount of electrical power they can safely deliver, their ability to dissipate waste heat, and their internal design enabling them to be serviced when under vibration, dust and temperature extremes. When such uncommon interior imagery does appear, like the pictures of the production of the 1RL257 Krasukha-4, the most informative things tend to be not the antennas, but instead the cabinets, harnesses, and cooling equipment that enables sustained jamming.
On a system level, the Krasukha-4 is shown as a two-vehicle configuration on an 8×8 KamAZ-6350 chassis, with the emitter car and a command-post car being separated. That division is an engineering hint: The high-power RF transmission, signal generation and control computing is more demanding in terms of power conditioning, electromagnetic compatibility and heat rejection. Having larger functions in different trucks minimizes the issue of coupling, makes maintenance easier to access, allows designers space in which to design dedicated airflow paths, liquid loops, and shock-isolated electronics bays without pushing all the functions into a single tight compartment.
The inevitable side effect of contemporary radar and EW is the thermal burden. With large systems, the amount of waste heat may be tens to hundreds of kW not only at the final RF stages but distributed electronics along the antenna and control chain. Those losses accumulate in areas that are difficult to cool densely populated power amplifiers, high-current supplies, and processing modules that must be stable in temperature to provide predictable operation. The further a jammer attempts to extend its effective range or to a broader bandwidth the greater the stress it places on its thermal-management system at maintaining the parts within narrow limits as the vehicle bears the shock, vibration, and other severe weather limitations.
Therein lies where internal layout will be performance. Cable lengths are kept very short to minimize loss and unwanted emissions, whereas tight packing of cables maximizes the local heat flux. Ruggedized designs may simply be built on conduction paths, such as spreader plates and chassis structures, simply to conduct the heat off the hotest components. Conventional aluminum spreaders are useful in terms of weight and manufacturability, however, thermal conductivity of about ~180 W/m-K can still permit damaging hot spots. Passive two-phase heating of embedded heat pipes within structural plates is the industry solution to many high-density modules. These “high thermal conductivity plates” have been used in radar-class electronics, where it has been shown to have a range of between 500 and 1200 W/m-K with a step change in heat spread without the addition of pumps or electrical power consumption.
After the heat is dispersed, it must get out of a car. Liquid cooling loops are also used to cool high-power radar and EW cabinets, as air cooling cannot handle the waste-heat and environmental constraints at a practical fan size and noise. Single-phase glycol-water loops are historic and easier but two-phase pumped systems have the chance to locate electronics closer to the average temperature since much of the heat is taken up during the phase transition of the fluid, instead of through elevating bulk fluid temperatures. That stricter isothermality is not a scholarly virtue; it enhances reliability, maintains calibration drift at a lower level, and can do without the excessive size and pressure of pumps to scale up flow rates.
The final hard boundary is heat rejection. This is not always sufficient in many defense applications, so the systems can employ chillers to precondition the loop and maintain electronics down to below ambient air temperatures. The chiller components, compressor, radiator, fans, controls, etc., also have to endure the same harsh environment as the rest of the vehicle, so the mechanical packaging enclosing such components may be as informative as the RF hardware.
The priorities are already indicated by enclosure practices and production imagery even without a complete schematic. Instructions on rugged rack integration include MIL-STD environmental survivability, clean cable routing, and zoning of thermal considerations particularly when sealed to AEM is required since compact electronics need a predictable airstream and rapid access to service. Concisely, the interior of a contemporary jammer is an atlas of limits: the distribution of power which has the ability to operate transmission, the cooling structure dimensioned to support uninterrupted heating, and a layout enabling the entire machine to be maintainable under the most inhospitable circumstances.
