5:1 CUBE™ Unun – Model CU-5-1500 (50:250 Ohm, 1.8-61 MHz, 1.5KW PEP)
Application. For traveling wave, end fed or portable 20-31 foot vertical antennas the 5:1 unun makes a good transformer for converting 50 ohm coax to a 250 ohm feed point. If you use the antenna on multiple bands, the feed point impedance may not always be 250 ohms and use of the unun at high (>350 ohms) or low (<100 ohms) will require reduced power input or the unun may have its power ratings exceeded and damage to the unun may occur. The (5:1 conversion ratio will change for loads other than 250 ohms unbalanced.
Typical application:
Also available as a balanced output – CB-5-1500
FSB31-1-1, ID=1", RFI Range 1-300 MHzProduct DetailsMPN: FSB31-1Initial Permeability (@ 10KHz): 1500Material: MnZnMax cable size - in/mm: 1.0/25.4OD (A) - in/mm: 2.22/56.4ID (B) - in/mm: 1.02/25.9Length (C) - in/mm: 1.69/41.9Z (ohms per bead - single turn 1 MHz): 45Z (ohms per bead - single turn 5 MHz): 90Z (ohms per bead - single turn 10 MHz): 125Z (ohms per bead - single turn 25 MHz): 218Z (ohms per bead - single turn 100 MHz): 375Z ohms (per bead - single turn 250 MHz): 340Case/Box lot size: 36Also known as Big Clamp On. Very useful for AC/DC power, coax cable, etc. Use multiple turns for best results or multiple chokes in series (recommended for large amperage power cables). Always put +/- dc cables through the same ferrite filter so their fields cancel and the ferrite suppresses the common mode current on each cable.
These ferrites also work well for coax feed line chokes. Use 3 turns of RG-213 size coax thru center and put several ferrite in series each with 3 turns to make an excellent 80-10 meter high power feed line choke.
Also known as Big Clamp On. Very useful for AC/DC power, coax cable, etc. Use multiple turns for best results or multiple chokes in series (recommended for large amperage power cables). Always put +/- dc cables through the same ferrite filter so their fields cancel and the ferrite suppresses the common mode current on each cable.
These ferrites also work well for coax feed line chokes. Use 3 turns of RG-213 size coax thru center and put several ferrite in series each with 3 turns to make an excellent 80-10 meter high power feed line choke.