EF14 Trimmer Capacitor Equivalent & Substitute Parts

Part Overview

The EF14 is a 0.8–14pF trimmer capacitor manufactured by Knowles Voltronics, designed for through-hole mounting applications requiring top adjustment. This component features a PTFE dielectric, rated for 125V operation across a temperature range of -65°C to 125°C. The EF14 is classified as obsolete, making identification of suitable substitute components essential for ongoing design support and production continuity.

Substiute Parts

EF14

Knowles VoltronicsIn Stock: 958EF14 Datasheet

Current PartRFQ

AF14

Knowles VoltronicsIn Stock: 1232AF14 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the EF14 is determined by the following critical parameters:

• Capacitance Range Overlap: The substitute must cover the required tuning range within the application's specifications
• Voltage Rating: Minimum 125V to maintain electrical safety margins
• Adjustment Type: Top adjustment mechanism for mechanical compatibility
• Physical Dimensions: Identical diameter (0.300") and height (0.480") for PCB footprint compatibility
• Mounting Type: Through-hole configuration for circuit board integration
• Operating Temperature Range: Support for -65°C to 125°C operational envelope
• Q Factor Performance: Minimum 3000 @ 100MHz for RF/microwave applications

The AF14 meets all substitution criteria with the exception of dielectric material (air vs. PTFE) and capacitance range minimum (1pF vs. 0.8pF). These differences are acceptable where the application does not require sub-1pF tuning capability.

Parameter Comparison

Engineering Selection Recommendations

The AF14 is a direct functional substitute for the EF14 based on electrical and mechanical parameter alignment. The AF14 offers the following advantages:

• Active Product Status: The AF14 remains in active production, ensuring long-term availability and supply chain stability
• Regulatory Compliance: ROHS3 compliance and REACH unaffected status provide environmental and regulatory assurance
• Identical Performance Metrics: Matching Q factor, voltage rating, and temperature range ensure equivalent RF performance
• Mechanical Compatibility: Identical physical dimensions guarantee PCB footprint compatibility without redesign

The capacitance range difference (1–14pF vs. 0.8–14pF) is acceptable for applications where minimum tuning values of 1pF or greater satisfy circuit requirements. Verification of the application's minimum capacitance requirement is necessary before final selection.

Frequently Asked Questions (FAQ)

Q: Can the AF14 directly replace the EF14 in existing designs?

A: Yes, provided the application does not require capacitance values below 1pF. The AF14 covers the 1–14pF range, which overlaps with the EF14's tuning capability. Physical dimensions and electrical performance are identical.

Q: What is the significance of the dielectric material difference (PTFE vs. Air)?

A: PTFE and air dielectrics exhibit different temperature coefficients and stability characteristics. The AF14's air dielectric provides excellent frequency stability and low loss. Selection depends on the specific application's temperature stability and frequency response requirements.

Q: Are there any compliance or regulatory differences between the EF14 and AF14?

A: The AF14 is ROHS3 compliant and REACH unaffected, providing regulatory assurance for modern manufacturing environments. The EF14's compliance status is not specified in available documentation.

Q: What packaging options are available for the AF14?

A: The AF14 is supplied in bulk packaging, suitable for high-volume production environments.

Q: Is the AF14 suitable for RF and microwave applications?

A: Yes. The AF14 maintains a Q factor of 3000 @ 100MHz, matching the EF14's performance specification and supporting RF/microwave tuning applications.