Hammond 107R 10K:4K Ohm Center-Tapped Miniature Audio Transformer

The 107R is a 107 Series miniature audio transformer that couples a 10K ohm centre-tapped primary (pins 1-3) to a 4K ohm centre-tapped secondary (pins 4-6) at a 1.58:1 turns ratio. It fits audio input, line matching and isolation tasks between two relatively high-impedance circuits on a PC board.

Power level is 150mw from 150 Hz. to 50 Khz., with a frequency range of 150 Hz. to 80 Khz. +/- 1.5db at +0, +10 and +20 dbm (no D.C. saturation) and a frequency response of ±1.5db from 300Hz to 50KHz. Typical DCR is 720 ohms primary (410/310 ohms) and 350 ohms secondary (175/175 ohms); the ordering table gives 680 and 390 ohms (+/- 20%). Inductance is 9.20 Hy primary and 3.88 Hy secondary, and impedance 44.4 K and 18.5 K ohms, at 1.0 kHz, 1.0 V. Maximum D.C. unbalance is 1.5 mA and dielectric strength 100 Vrms.

Every 107 Series unit is epoxy potted in an attractive black molded case, and the rugged potting produces a completely sealed part that withstands severe environmental conditions. It will withstand soldering for 10 sec. at 260 degrees C, with a maximum ambient temperature of 85 degrees C; the casting epoxy has a workable range of -40°C to +105°C under a normal rate of change, not including thermal shock. According to the drawing, either winding may be used as the primary.

It mounts on a PC board with pin-type terminals of min. 0.187" length and is RoHS and REACH compliant, with a shipping weight of 0.02 lbs (0.01 kg).