The MEF-107-2k+ is new high power EFHW antenna transformer(~50:1 ratio) designed with massive 1.25 pound (0.57kg) ferrite core, equivalent of almost six (6) 2.4-inch toroids and very low insertion loss for frequencies from 1-7MHz
Insertion loss measurement S21 with two back to back transformers shows only 0.18dB (4% power loss) at 160m and 0.28dB (6% power loss) on 40m bands.