The **NP3CM-R** is a specialized 1/4" (6.35 mm) 3-pole (TRS) professional phone plug manufactured by **Neutrik**. It is specifically designed for military-style applications and patching systems, often referred to as a "B-Gauge" or "MIL-type" connector. --- ### ## Technical Specifications Below are the primary electrical and mechanical characteristics of the NP3CM-R: | Feature | Specification | | :--- | :--- | | **Connector Type** | 1/4" Phone Plug (TRS - Tip, Ring, Sleeve) | | **Contact Plating** | Brass (CuZn39Pb3) | | **Shell Material** | Brass (CuZn39Pb3) with Red plastic coating | | **Rated Voltage** | < 50 V | | **Insulation Resistance** | > 2 GΩ (initial) | | **Dielectric Strength** | 1 kVdc | | **Cable O.D.** | 4 - 7 mm | | **Standard Compliance** | MIL-P-642/5A | --- ### ### Key Electronic & Design Features 1. **MIL-P-642/5A Standard:** Unlike standard consumer 1/4" jacks, the NP3CM-R is built to military specifications. This ensures a more precise tip shape and tighter tolerances for reliable contact in high-density patch bays. 2. **B-Gauge Compatibility:** This is a "B-Gauge" plug. While it looks like a standard guitar jack, the tip is slightly different (smaller and more rounded), meaning it is intended for use with **B-Gauge TB (Tiny Telephone) or MIL-type jacks**, not standard 1/4" musical instrument jacks. 3. **Construction (The "R" Suffix):** The "R" in the part number stands for **Red**. The shell is covered in a durable red plastic, which serves two purposes: * **Identification:** Easy visual coding in complex patching environments. * **Insulation:** Provides a non-conductive grip surface. 4. **Solderability:** The internal terminals are designed for high-quality soldering. It features a chuck-type strain relief system that protects the electronic connection from physical tension or cable pulling. --- ### ### Wiring Diagram The NP3CM-R follows the standard TRS (Balanced) wiring convention: ```text Terminal | Signal Type | Typical Use (Balanced) ---------|-------------|---------------------- Tip | Positive | Hot (+) Ring | Negative | Cold (-) Sleeve | Ground | Shield / Earth ``` --- ### ### Usage Note **Warning:** Do not use the NP3CM-R in standard commercial audio equipment (like a guitar amp or a standard mixing console input). Because it follows the MIL-P-642/5A standard, the physical dimensions of the tip can cause poor contact or even physical damage to standard 6.35mm jacks that are not B-Gauge rated.