With the LFB - series Laird has developed a ferrite material, which has good suppression in the short wave range up to 30 MHz. Because of a higher initial permeability of 5000, this material is better than -3S4 material up to about 10Mhz. The LFB material therefore is more suitable for the synthesis of low-band choke baluns for 160,80 and 40m.
Data: outer diameter 9.5 mm - inside diameter 5.1 mm - Length 19mm
initial permeability: approx. 5000
Practical impedance measurements (8 cores measured on the shield of a coaxial cable RG58 with AEA CIA-HF Analyzer):
1.8 Mhz - 700 ohms; 3.6 Mhz - 900 ohms; 7.0 Mhz - 910 Ohm, 28 MHz 350 Ohm