1500 Watt 4:1/9:1 CUBE Unun™ – Model CU-4-9-1500
Model CU-4-9-1500 is a 4:1 and a 9:1 unun housed in a NEMA enclosure box (4″ x 4″ x 2″) with one eyebolt for 9:1 and a side stud for 4:1 outputs, each capable of input power levels up to 1500 watts PEP when used with a matched load. The 4:1 ratio takes 50 ohms input and matches to 200 ohms output and the 9:1 ratio takes 50 ohm input and matches to 450 ohms output between 1-60 MHz.
A great multipurpose unun for 31′ fiberglass verticals, end fed non-resonant long wire antennas, traveling wave verticals, etc. Multi-core unun with side ground terminal for adding counterpoise or radials as an option. Now you don’t need two ununs – just pick the output ratio that best matches your antenna tuner! Only ONE ratio can be used at a time.Choose wither the 4:1 (left side terminal) and ground OR the 9:1 (top eyebolt terminal) and ground.
The Unun provides multiple taps for impedance conversions of:
- 50 to 450 (9:1) – for end fed long wires, traveling wave antennas
- 50 to 200 (4:1) –for ¼ wave vertical folded dipoles, OCF end fed antennas
This unun is designed to convert unbalanced coax to an unbalanced antenna feed point such as vertical antennas, low impedance end fed antennas, traveling wave antennas, etc.
Attach the feedline to the SO-239 coax connector and a ground to the side ground post (which is internally connected to the coax connector shield).Connect the antenna radiating element to either the “4” side terminal for 200 to 50 ohm matching or the “9” top terminal for 450 ohm matching.
The CU-4-9-1500 is a matching transformer and NOT a common mode choke/line isolator.For best results, use a 1:1 common mode choke (CU-1-1500SO or MC-1-3000) or coax noise filter (CMNF-1500) at the radio end of the coax to keep transmitted RFI from getting into the radio and also to reduce receive noise