The **CTC1F-R18M** is a high-frequency, axial-leaded ceramic core inductor. It is part of the CTC1F series manufactured by Central Technologies (and similar manufacturers like Coilcraft or Taiyo Yuden in equivalent series). Below is a detailed breakdown of its electronic specifications and characteristics. --- ### 1. General Specifications The part number "R18M" defines the inductance value and tolerance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 0.18 µH (Microhenries) | | **Tolerance** | ±20% (indicated by the "M") | | **Package Type** | Axial Leaded (Through-hole) | | **Core Material** | Ceramic (Phenolic) | | **Coating** | Conformal Coated (Epoxy) | --- ### 2. Electrical Performance Inductors of this size and material are designed for high-frequency stability rather than high power. | Feature | Value (Typical) | | :--- | :--- | | **Q-Factor (Min)** | 40 (at 25.2 MHz) | | **Self-Resonant Frequency (SRF)** | ~550 MHz | | **DC Resistance (DCR Max)** | 0.20 Ohms | | **Rated DC Current (Idc)** | ~900 mA | --- ### 3. Key Components and Construction * **Ceramic Core:** Unlike ferrite cores, ceramic (phenolic) cores have very low permeability. This makes the inductor highly stable across a wide range of frequencies and temperatures, with no risk of core saturation. * **Winding:** Fine copper wire wound around the ceramic cylinder. * **Encapsulation:** Usually protected by a flame-retardant epoxy coating which provides environmental protection and insulation. * **Color Coding:** Many axial inductors use a color-band system (similar to resistors) to denote value and tolerance. --- ### 4. Common Applications Due to its low inductance (0.18 µH) and high resonant frequency, the CTC1F-R18M is typically used in: * **RF Tuning:** Oscillators and high-frequency filter circuits. * **Signal Decoupling:** Removing high-frequency noise from signal lines. * **Telecommunications:** Infrastructure and wireless communication devices. * **Impedance Matching:** Used in antenna circuitry to match source/load impedance. --- ### 5. Identification (Part Number Breakdown) * **CTC1F:** Series designation (Conformal Coated Axial Inductor). * **R18:** The value. "R" acts as a decimal point. $0.18$ units ($\mu H$). * **M:** Tolerance code. $M = \pm20\%$, $K = \pm10\%$, $J = \pm5\%$.