146I

Overview

The Hammond Manufacturing 146I is an audio chassis mount transformer designed for signal applications. It features a primary impedance of 500 ohms with a center tap and a secondary impedance of 8 ohms. The device operates within a frequency range of 150 Hz to 15 kHz. Primary resistance is specified at 26 Ohms, while secondary resistance is 700 mOhms. This component utilizes a small, open construction suitable for horizontal bracket mounting.

Feature Summary

• Small, economical, open design with two-hole horizontal bracket mounting capability
• Insulated, color-coded flexible leads providing minimum 3-inch length
• Center-tapped primary winding configuration for balanced audio signal handling

Applications

• Audio output stage coupling in tube amplifier circuits
• Impedance matching between vacuum tube stages and speaker loads
• Balanced-to-unbalanced signal conversion in professional audio equipment

Procurement Notes

Verify the specific impedance ratio and lead length requirements against the original circuit schematic before procurement. Confirm that the chassis mounting hole spacing aligns with the existing enclosure design. Ensure the operating frequency range meets the application's bandwidth needs. Check RoHS compliance status if environmental regulations apply to the final assembly.

Selection Notes

Select this transformer when a compact, cost-effective solution is required for low-power audio output stages. Consider the 500-ohm primary impedance compatibility with the preceding tube or circuit stage. Evaluate the physical dimensions to ensure fit within the designated chassis area. Verify that the 8-ohm secondary matches the connected load impedance for optimal power transfer.

Part Context

The 146I belongs to the Hammond 143-146 series of audio chassis mount transformers. This series is characterized by its economical pricing and compact form factor. These components are widely used in vintage and modern audio amplifier designs requiring reliable isolation and impedance transformation between circuit stages.

Replacement Considerations

Direct substitutes include other Hammond 143-146 series variants such as the 146S, though impedance ratios may differ. Cross-reference with equivalent models from other manufacturers ensuring identical 500CT:8 ohm specifications and mounting dimensions.