50:300/75:450 (6:1) CUBE™ Unun, 1-31 MHz, Receive Only (choose top stud/eyebolt/input connector)
6:1 CUBE Unun – Receive Only Applications (vertical, end fed antennas)
Model CU-6-RX-50 is a 6:1 (300:50) unun housed in a NEMA enclosure box with a single eyebolt/halyard hoist at the top, ground stud on the side and input connector (N or SO239) at the bottom. The 6:1 ratio takes 50 ohms input and matches to 300 ohms output from 1-31 MHz with SWR < 1.5:1 under matched load conditions. A 75 ohm input cable will be matched to 450 ohms (6:1).
Typical SWR and impedance transformation from 1-61 MHZ shown below:
This transformer requires a feed line choke to isolate the coax feed line from the antenna. A coax noise filter such as the CMNF-500-50 installed at the receiver end of the coax is also recommended.