CTI Audio Inc, - 41821 - Miniature Condenser Microphone Element, Felt Top.

CTI Audio Inc, - 41821 - Miniature Condenser Microphone Element, Felt Top. CTI Audio, Inc. (formerly Conneaut Technologies Inc./Astatic) was associated with and owned Astatic, a manufacturer of microphones, with records showing CTI Audio was later purchased by Omnitronics, LLC. A condenser microphone typically has three leads (or pins in an XLR connector) to support a balanced audio connection, which minimizes noise and interference over long cable runs. These three leads are for Pin 1 (Ground/Shield), Pin 2 (+/Hot), and Pin 3 (-/Cold). Key Reasons for Three Leads: • Balanced Signal Transmission: Pins 2 and 3 carry the same audio signal but with opposite polarity (inverted). The receiving device (mixer/preamp) compares the difference, canceling out any induced electrical noise. • Phantom Power Transmission: Condenser microphones require power to operate. A 48V phantom power is supplied from the preamp/mixer via Pins 2 and 3, using Pin 1 as the ground reference. • Noise Cancellation: The shield (Pin 1) protects the signal from electromagnetic interference (EMI), while the balanced + and - signals cancel out noise that penetrates the shielding. Measuring an open circuit (infinite DC resistance) and a low capacitance of 26- 30 pF indicates a condenser microphone element (specifically a bare capsule). Here is why your measurements match this type: • Open Resistance: Condenser capsules consist of two plates (a diaphragm and a backplate) separated by an air gap or insulator, forming a capacitor. Because they are not physically connected, they show "open" or infinite resistance when tested with a standard DC ohmmeter. • 26- 30 pF Capacitance: The typical capacitance of a precision condenser or electret capsule generally falls between 5 pF and 100 pF. A value of 30 pF is extremely common for standard 1/2-inch or 1/4-inch measurement microphone capsules. In essence, the three-lead design ensures clean audio transmission by combining grounding, power, and high-quality, interference-free audio signals in one cable. Dimensions: 10.6mm Tall x 10.0mm Diameter. 3-Radial Leads on Bottom of Element. A lead grounded, Across other two leads measured approximately 26 - 30pF. Aluminum Shell Manufacturer/Brand: Genuine CTI/Astatic parts are generally higher in price compared to unbranded replacements. Applications: These are frequently used for repairing older CB/Ham Radio microphones. Acquired from the Old Astatic Manufacturing Facility that closed down in Conneaut. Proudly Made in USA New Old Stock