Hammond 140TEX 1000 Ohm Shielded Audio Isolation Transformer

The 140TEX is a studio grade 1:1 audio transformer with a 1,000 ohm primary and a 1,000 ohm secondary. Its listed typical application is input/output isolation, and the drawing also lists line matching, driver and hybrid applications. Audio engineers and equipment designers can use it to break ground paths or isolate signal-level circuits without changing impedance.

The two windings are matched: primary (RED - YEL) and secondary (GRN - BLU) each measure 89.7 ohms DCR, 7.20 H inductance and 62.7 kOhm impedance at 1 kHz, 1 V.

An 80% nickel core provides high permeability combined with low losses, and the metal can shields against a broad range of external sources. The 140TEX operates over 20 Hz to 20 kHz (+/- 1 dB), is rated for 10.0 dBm output (marked 5 mW), and is designed for lowest distortion at +10 dBm or less. Insertion loss is under 1.0 dB, return loss 20 dB, longitudinal balance -65 dB and dielectric strength 500 Vrms.

It is a chassis mount, shielded transformer in a metal can with an adjustable height case bracket. The case is 1.00 in (25 mm) high and 1.25 in (32 mm) in diameter, mounting holes are listed at 1.88 in (48 mm), leads are 5.00 in (127 mm) long, and net weight is 3 oz (shipping weight 0.13 lbs / 0.06 kg). It is made in Canada and RoHS and REACH compliant.