Hammond 108E 600 CT to 3.2 Ohm Output Transformer, 500 mW

The 108E is a 500 mW miniature audio transformer from the 108 Series that steps a 600 ohm centre-tapped primary (pins 1-3) down to a 3.2 ohm secondary (pins 4-6). Its 13.71:1 turns ratio makes it an output transformer for driving a small 3.2 ohm load from a 600 ohm stage on a PC board.

Power level is 500mw from 300 Hz. to 50 Khz. At +0, +15 and +27 dbm the frequency range is 300 Hz. to 50 Khz. +/- 1.75db, measured with no D.C. saturation, and the frequency response is ±1.75db from 300Hz to 50KHz. Typical output power is 0.500 Watts. Typical DCR is 54 ohms primary (27/27 ohms) and 0.40 ohms secondary; the ordering table lists 65 and 0.43 ohms (+/- 20%). Inductance at 1.0 kHz, 1.0 V is 0.95 H primary and 5.5 mH secondary, leakage 2.60 mH, and impedance 8.20 K ohms and 53.5 ohms. Unbalanced DC is 6mA max., and 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). With no centre tap on its 3.2 ohm secondary, pin 5 is omitted; the drawing notes that the secondary may be used as primary and the primary as secondary.

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).