Bourns 3386G-1-503 Trimmer Potentiometer: Equivalent & Substitute Parts

Part Overview

The Bourns 3386G-1-503 is a 50 kOhm, 0.5W through-hole trimmer potentiometer with PC pin termination and top adjustment. This sealed Trimpot® 3386 series component is designed for precision circuit tuning applications requiring cermet resistive elements and single-turn adjustment capability. The part maintains active product status and is available in original stock quantities of 712 units. Equivalent and substitute parts are identified based on matching electrical specifications, mechanical compatibility, and functional performance within the allowed parameter tolerances for this trimmer potentiometer category.

Substiute Parts

3386G-1-503

Bourns Inc.In Stock: 7643386G-1-503 Datasheet

Current PartRFQ

25PR50KLF

TT Electronics/BIIn Stock: 1166425PR50KLF Datasheet

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72PR50KLF

TT Electronics/BIIn Stock: 140172PR50KLF Datasheet

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82PR50KLF

TT Electronics/BIIn Stock: 110082PR50KLF Datasheet

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M63P503KB40

Vishay SpectrolIn Stock: 1143M63P503KB40 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3386G-1-503 are qualified based on the following critical parameters that determine functional equivalence:

• Resistance value: 50 kOhms (exact match required)
• Power rating: 0.5W / 1/2W (exact match required)
• Tolerance: ±10% (exact match required)
• Temperature coefficient: ±100ppm/°C (exact match required)
• Number of turns: 1 (exact match required)
• Resistive material: Cermet (exact match required)
• Mounting type: Through Hole (exact match required)
• Termination style: PC Pins (exact match required)

Substitutes are grouped into two categories based on adjustment type and physical dimensions:

Category A: Top Adjustment, Square 0.375" x 0.375" (9.53mm x 9.53mm)

• 72PR50KLF (TT Electronics/BI Series 72)

Category B: Top Adjustment, Smaller Footprint

• 25PR50KLF (TT Electronics/BI Series 25) - Square 0.270" x 0.270" (6.86mm x 6.86mm)

Category C: Side Adjustment (Functional Equivalent with Different Adjustment Orientation)

• M63P503KB40 (Vishay Spectrol Series 63) - Square 0.395" x 0.395" (10.03mm x 10.03mm)

Parameter Comparison

Engineering Selection Recommendations

Direct Footprint Match (Recommended for Space-Constrained Designs): The 72PR50KLF (TT Electronics/BI Series 72) provides identical electrical specifications and physical dimensions (0.375" x 0.375" square) to the 3386G-1-503. This substitute maintains top adjustment orientation and is ROHS3 compliant with REACH unaffected status, offering improved regulatory compliance compared to the original part.

Space-Optimized Alternative: The 25PR50KLF (TT Electronics/BI Series 25) meets all electrical requirements with a reduced footprint (0.270" x 0.270" square). This option is suitable for designs where board space is limited and the smaller form factor is acceptable. The 25PR50KLF is RoHS compliant and REACH unaffected.

Compact Round Profile Option: The 82PR50KLF (TT Electronics/BI Series 82) provides a round 0.250" diameter profile, offering the smallest footprint among top-adjustment alternatives. All electrical parameters remain equivalent. This part is ROHS3 compliant and REACH unaffected.

Side-Adjustment Alternative: The M63P503KB40 (Vishay Spectrol Series 63) is functionally equivalent with side adjustment orientation instead of top adjustment. This part is suitable only for applications where side-mounted adjustment access is acceptable. The M63P503KB40 is ROHS3 compliant and REACH unaffected, with MSL rating of 1 (Unlimited).

All substitute parts maintain active product status and are available in original stock quantities.

Frequently Asked Questions (FAQ)

Q: Can the 25PR50KLF be used as a direct replacement for the 3386G-1-503 in existing PCB designs?

A: The 25PR50KLF is electrically equivalent but has a smaller physical footprint (0.270" x 0.270" versus 0.375" x 0.375"). It can be used if the PCB layout accommodates the reduced dimensions. The mounting hole spacing and PC pin configuration remain compatible with through-hole assembly processes.

Q: What is the primary difference between the 72PR50KLF and 82PR50KLF substitutes?

A: Both parts are electrically identical with matching electrical specifications. The 72PR50KLF maintains a square 0.375" x 0.375" profile identical to the original 3386G-1-503, while the 82PR50KLF uses a compact round 0.250" diameter profile. Selection depends on available PCB space and mounting hole configuration.

Q: Is the M63P503KB40 a suitable substitute if the application requires top adjustment?

A: The M63P503KB40 features side adjustment rather than top adjustment. It is functionally equivalent electrically but requires different physical access for tuning. Use this substitute only if the application design accommodates side-mounted adjustment access.

Q: What are the compliance differences between the original 3386G-1-503 and the substitute parts?

A: The 3386G-1-503 is RoHS non-compliant and REACH affected. All substitute parts (25PR50KLF, 72PR50KLF, 82PR50KLF, and M63P503KB40) are ROHS3 compliant and REACH unaffected, offering improved regulatory compliance for new designs and applications with environmental requirements.

Q: Are there packaging considerations when selecting a substitute?

A: The 3386G-1-503 is supplied in tube packaging. The 25PR50KLF is also available in tube packaging, while 72PR50KLF, 82PR50KLF, and M63P503KB40 are supplied in bulk packaging. Packaging selection may affect procurement quantities and handling procedures.

Q: Can substitutes be mixed within a single assembly?

A: All substitute parts meet identical electrical specifications (50 kOhms, 0.5W, ±10% tolerance, ±100ppm/°C temperature coefficient, 1-turn cermet). They can be used interchangeably within the same circuit if physical dimensions and adjustment orientation are compatible with the PCB layout and mechanical design.