The 148F is an open-frame audio driver transformer for printed circuit boards that pairs a 1500 ohm primary with a dual 125/500 ohm secondary. It is part of the 148 Series of audio open-frame transformers and is aimed at designers and OEM builders who need a board-mounted driver transformer in a small signal-level audio circuit.
Maximum primary D.C. current is 11.6 mA, D.C. resistance is 220 ohms primary and 58 ohms secondary (+/- 15%), and output is 75 mW. The primary impedance here is taken from the series ordering table.
The transformer uses economical, open-type horizontal bracket construction with pin terminals 0.25 in long and 0.025 in square for P.C. board mounting. Windings are bifilar wound for balanced capacitive and resistance characteristics, on pin bobbins for standard 0.2 in grid pin spacing. Pins are not labeled; a dot marks pin 1, and the remaining pins follow from the schematic. Net weight is 0.6 oz for the 148 Series.
Frequency response is 200 Hz to 15 kHz (+/- 1 dB, referenced at 1 kHz), insertion loss is less than 1/2 dB and the insulation test is 250V rms. Total distortion is approximately 2% for drivers at 200 Hz, decreasing at higher frequencies. The 148F is RoHS and REACH compliant. For rugged epoxy cast units the manufacturer refers to its 102, 104, 106 or 107, 108 and 109 series.
| Series | 148 Series (Audio Open Frame, PC Board Mount) |
| Application | Driver |
| Product Type | Audio transformer, open frame PC board mount |
| Manufacturer Short Description | AUDIO TX DRIVER PC MOUNT |
| Output | 75 mW |
| Insertion Loss | Less than 1/2 dB |
| Insulation Test | 250V rms |
| Total Distortion | Approximately 2% for drivers at 200 Hz, decreasing at higher frequencies |
| Frequency Response | 200 Hz to 15 kHz (+/- 1 dB, ref. @ 1 kHz) |
| D.C. Resistance Note | Figure is for the total primary or secondary winding (multiple windings connected in series) |
| Primary D.C. Resistance | 220 ohms +/- 15% |
| Schematic Drawing Figure | 2 |
| Max. Primary D.C. Current | 11.6 mA |
| Primary Nominal Impedance | 1500 ohms |
| Secondary D.C. Resistance | 58 ohms +/- 15% |
| Secondary Nominal Impedance | 125/500 ohms |
| UPC | 623980197807 |
| UNSPSC | 39121301 |
| Part Number | 148F |
| Shipping Weight | 0.05 lbs (0.02 kg) |
| Pins | 0.25 in length, 0.025 in square |
| Winding | Bifilar wound on pin bobbins for balanced capacitive and resistance characteristics |
| Mounting | P.C. board mount, pin type |
| Net Weight | 0.6 oz (148 Series) |
| Pin Spacing | Standard 0.2 in grid |
| Construction | Economical, open type, horizontal bracket |
| Pin Identification | Pins not labeled; a dot indicates pin 1 |
| Epoxy Cast Alternatives | 102, 104, 106 or 107, 108 and 109 series |
| RoHS Compliant | Yes |
| REACH Compliant | Yes |
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Both have a 125/500 ohm secondary and a 75 mW rating. The 148F has a 1500 ohm primary and 11.6 mA maximum D.C. current; the 148E has a 500 ohm primary and 18 mA.
It is a P.C. board mount part with pins 0.25 in long and 0.025 in square, on pin bobbins for a standard 0.2 in grid. The open horizontal bracket construction has no clinching lugs; those are a feature of the 149 Series.
Pins are not labeled on the unit. A dot indicates the position of pin 1, and the other pins can be determined from the series schematic.
200 Hz to 15 kHz, +/- 1 dB, referenced at 1 kHz, with insertion loss less than 1/2 dB.
220 ohms primary and 58 ohms secondary, +/- 15%, measured for the total winding with any multiple windings connected in series.
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