End Fed Antenna Matcher (9:1) CUBE™ Unun, 1.5KW - .6-60 MHz
NEW improved version with 8 ferrite cores for higher duty cycle power limit and frequency range from 600 KHz to 45 MHz under 2:1 SWR or to 350 KHz to 60 MHz under 3:1 SWR
Description: Model AM-9-1500 is a 450 ohm to 50 ohm (9:1) quad core, unun housed in a NEMA enclosure box (4″ x 4″ x 2″) with top halyard hoist/antenna feed point and a side stud used for a counterpoise or radial connection.This antenna matcher is typically used with end fed non-resonant antennas with feed point ranges from 300-900 ohms at RF power levels up to 1500 watts PEP when used with a matched load. With a matched 450 ohm load the SWR over the frequency range 600 KHz to 45 MHz is less than 2:1 on the coax feed side.
Application: For non-resonant end fed and certain types of telescoping vertical antennas, the 9:1 balun makes a good transformer for converting to 50 ohm coax to the 450 ohm feed point.If you use the antenna on multiple bands, the feed point impedance may not always be 450 ohms and use of this matcher at high (>600 ohms) or low (<300) will require reduced power input or the matcher may have its power ratings exceeded and damage may occur. The (9:1 conversion ratio may change for loads other than 450 ohms balanced).
Recommended max RTTY or digital mode (FT-8, PSK, etc) of 750 watts with 50% on/off duty cycle. 1500 watts CW or SSB.