These baluns and ununs can be used for impedance matching and also as End Fed halfwave antenna matching transformers to 50 or 75 ohm coax cable.
FT240-3I, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, Mini Pack of 3
Product Details
MPN: F240-31-3
Country/Region of Manufacture: China
RFI Range (MHz): 1-300 Mhz
ID-B (in/mm): 1.4/35.6
OD-A (in/mm): 2.4/61
Height-C (in/mm): .5/12.7
Weight (oz/gm): 188 grams
Initial permeability: 1500
Case/Box lot size: 100
Minipack of 3 ferrite ring cores - Very useful for AC/DC power, coax cable common mode current suppression. For highest choking resistance, wrap cable through center of ring as many turns as possible. DO NOT use for impedance transformers (2:1, 4:1, 9:1, etc.) - use Mix 43 or Mix 61 for high power.