Model CU-9-5000 is a 9:1 multi-core unun housed in a NEMA enclosure box (4″ x 4″ x 2″) with top stud/eyebolt output used to translate a 50 ohm input up to 450 ohms at RF power levels up to 5000 watts PEP (SSB) when used with a matched load. Usable to 61 MHz under 2:1 SWR with matched load.
Great for end fed antennas - FT-8 and digital mode power ratings are approximately 30% of PEP ratings into a matched 450 ohm load. For non-resonant end fed antennas, you will need a feed line choke on the coax. See typical antenna configuration notes below for details.
Non-Resonant End Fed Antenna Configuration Notes
50 ohm coax to 75 ohm balanced output baluns are useful for low (< 1 wavelength) dipoles exhibiting 75 ohm characteristic impedance or for matching to balanced ladder line whose endpoint impedance is near 75 ohms.
50 ohm coax to 75 ohm CATV coax connections are easily done with a 1.5:1 unun with SO-239 connectors on input and output. Likewise 50 ohm coax to unbalanced verticals or loads near 75 ohms can be matched with a 1.5:1 unun.