top of page
Search

Why does this licensed radio not need a Contains FCC ID label for its Bluetooth WiFi module?

The Bluetooth WiFi module was fully evaluated as part of the host radio certification rather than approved by reference. During certification testing for Parts 22, 74, 80, and 90, the Bluetooth/Wi-Fi functionality was installed, powered, and operating in the final product configuration. Compliance was demonstrated with the module in place, indicating that the FCC evaluated the Bluetooth/Wi-Fi transmitter as part of the complete host system. Because the host authorization does

Pre-Compliance Testing: Where Programs Are Saved or Lost

Skipping pre-compliance testing is particularly dangerous with MIL-STD-461G. Failures are rarely marginal—a CS or RS failure. Pre-compliance testing plays a decisive role in programs subject to MIL STD 461G. Skipping this step is particularly risky because failures under this standard are rarely small or easily corrected. When a system fails a conducted susceptibility or radiated susceptibility test, the result almost always indicates a structural weakness in the design rathe

Cables as Antennas: Why Geometry Beats Component Choice

In a significant number of MIL-STD-461G failures, the root cause is not the electronic circuitry but the external cabling. Cables frequently dominate electromagnetic coupling paths because their physical dimensions and routing allow them to interact strongly with both conducted and radiated fields. Cable length, routing, separation from structure, and termination geometry often determine how energy enters or leaves a system. Even when internal circuitry is well designed and a

RS105: Designing for Survival, Not Graceful Degradation

RS105 is intended to evaluate system behavior under exposure to extremely high-intensity transient electromagnetic fields that can result from severe external events. These conditions are far beyond normal operational interference and are meant to stress the limits of system robustness rather than functional performance margins. The expectation during RS105 testing is not graceful degradation or temporary loss of function. The requirement is survival. The equipment must not s

When Enclosures and Seams Start Talking

MIL STD 461G extends RS103 radiated susceptibility testing up to 18 GHz to represent the electromagnetic environments created by modern military systems. Contemporary platforms operate alongside high-frequency radars, data links, and electronic warfare emitters that produce fields well above the ranges traditionally emphasized in older standards. At these frequencies, the dominant coupling mechanisms change. Enclosure seams, fasteners, apertures, connector interfaces, and cab

CS116: Transient Immunity Is Not RF Immunity

CS116 introduces fast-damped sinusoidal transients rather than continuous or steady-state radio-frequency energy. The test simulates transient disturbances that propagate through cables and wiring due to switching events, inductive loads, or external electromagnetic disturbances. These events are short but high in energy and can couple deeply into internal circuitry. This test places primary emphasis on transient-protection strategies, including TVS diode selection and placem

CS114: The Test That Exposes Cable and Grounding Myths

CS114 is often the most punishing test because it bypasses enclosure shielding entirely. RF current is injected directly onto cables, forcing the design to rely on filtering, shield termination, and grounding integrity. Designs that lean too heavily on enclosure shielding frequently fail CS114. Cable entry points, not metal boxes, determine success here. Poor terminations and high-impedance grounds are exposed instantly.

CE102: Where Power Integrity Becomes a Platform-Level Risk

CE102 measures RF noise conducted back onto power leads. On military platforms, power is shared across multiple subsystems. Excessive CE102 emissions do not stay local—they propagate through the distribution network and couple into unrelated equipment. This is why CE102 failures are treated seriously. A noisy power interface can destabilize avionics, navigation systems, or mission electronics that are otherwise well designed.

The Most Common Failure Mode: Treating 461G Like Civilian EMC

Many failures trace back to a single root cause: designers approaching MIL-STD-461G as if it were FCC or CE compliance. Civilian standards tolerate weak grounding, floating enclosures, and casual cable routing. MIL-STD-461G assumes the environment will exploit those weaknesses aggressively. If grounding and bonding are afterthoughts, the test campaign will expose that immediately, usually during conducted susceptibility testing.

Tailoring Is an Engineering Decision, Not Administrative Paperwork

MIL STD 461G is intentionally written to require engineering judgment. It assumes that test requirements will be tailored based on the actual installation environment, the intended platform, the power architecture, and the cable configuration. Applying every available test without discrimination does not increase rigor. It increases risk. Poor tailoring leads to failures irrelevant to real-world operation, drives unnecessary test scope, and inflates cost and schedule without

bottom of page