Hammond 108J 1K:600 Ohm Center-Tapped Audio Transformer, 500 mW

The 108J is a 108 Series miniature audio transformer with a 1K ohm centre-tapped primary (pins 1-3) and a 600 ohm centre-tapped secondary (pins 4-6), a 1.29:1 turns ratio. It suits line matching from a 1000 ohm source to a 600 ohm line, as well as audio input, isolation and output applications on a PC board.

Typical output power is 0.500 Watts; the part drawing lists a power level of 150mw from 300 Hz. to 50 Khz. At +0, +10 and +20 dbm the frequency range is 300 Hz. to 50 Khz. +/- 1.5db without D.C. saturation, and the frequency response is ±1.5db from 300Hz to 50KHz. Typical DCR is 88 ohms primary (44/44) and 66 ohms secondary (33/33); the ordering table lists 109 and 69 ohms (+/- 20%). Inductance is 1.95 H primary and 1.12 H secondary, leakage 3.67 mH, and impedance 18.8 K and 11.4 K ohms at 1.0 kHz, 1.0 V. Unbalanced DC is 4.5mA max.; dielectric strength is 100 Vrms.

Like the rest of the 108 Series, it is epoxy potted in an attractive black molded case that forms a completely sealed unit able to withstand severe environmental conditions. It withstands soldering for 10 sec. at 260 degrees C with ambient temperature 85 degrees C max., and the casting epoxy is workable from -40°C to +105°C under a normal rate of change (thermal shock excluded). The drawing notes that primary and secondary may be swapped.

It mounts on a PC board with pin-type terminals of min. 0.187" length, is RoHS and REACH compliant, and has a shipping weight of 0.08 lbs (0.04 kg).