Part Number: 6278280121
78 RM CORE SET
RM (Rectangular Modulus) cores allow better shielding than E type geometries while also providing easier winding accessibility and better power dissipation than a pot core configuration. Fair-Rites standard RM cores all have a solid center post and standard height, low profile and alternate materials are available upon request.
RM cores can be supplied with the center post gapped to a mechanical dimension or an AL value.
Weight indicated is per pair or set.
Weight: 22 (g)
Chart Legend
•Dimensions (Top numbers are in millimeters, bottom numbers are in nominal inches.).
| Dim | mm | mm tol | nominal inch | inch misc. |
| A | 27.8 | ± 0.60 | 1.094 | _ |
| B | 9.3 | ± 0.15 | 0.366 | _ |
| C | 13.25 | ± 0.25 | 0.522 | _ |
| D | 6.4 | ± 0.20 | 0.252 | _ |
| E | 21.65 | ± 0.45 | 0.852 | _ |
| F | 10.65 | ± 0.20 | 0.419 | _ |
| G | 12.5 | min | 0.493 | min |
| J | 24.15 | ± 0.55 | 0.951 | _ |
Chart Legend
Σl/A : Core Constant, le : Effective Path Length, Ae : Effective Cross-Sectional Area, Ve : Effective Core Volume
AL : Inductance Factor 
Explanation of Part Numbers: Digits 1 & 2 = product class and 3 & 4 = material grade.
| Electrical Properties | |
| AL(nH) | 4200 ±25% |
| Ae(cm²) | 0.898 |
| Σl/A(cm⁻¹) | 5.3 |
| le(cm) | 4.79 |
| Ve(cm³) | 4.306 |
| Amin(cm²) | 0.884 |
AL value is measured at 1 kHz, B < 10 gauss.