5000 Watt Rated 1:1 CUBE™ Choke - .2-5 MHz (effective to 100 KHz)
Th CU-1-5000LF unun is useful as common mode feed line chokes or coax to antenna interfaces. SO-239 output models can also be used with balanced antennas if a short coax cable “pigtail” is used on the output and connected to the antenna. Rated 5000 Watts PEP from .2-5 Mhz. Use as line isolator, antenna interface, or as a common mode choke to keep RF on the antenna and off the outside of the coax braid.
These high powered chokes are more effective then our sleeve feed line chokes due to multi-turn ferrite bead topology using high permeability ferrite cores which provides a higher choking impedance over a broad frequency range. Typical common mode rejection (CMRR) is 30-42 over the frequency range (see graph) For most effective results, use 1 choke at the antenna feed point to keep transmit RF off the coax braidand another at the radio end of the coax. Helps reduce noise floor too by choking off common mode neighborhood noise picked up on outside of coax braid.
Available in 1.5K and 5K PEP models. Picture shows 1.5KW model, but 5KW model is same size and frequency specs but 5KW PEP.
A simple ferrite ring filter on the DC power line can help suppress the RFI noise affecting the victim device or keep the DC power cord from acting as an antenna and radiating RFI into other victim devices. This kit is also useful on laptop computer supplies, routers, cable modems, wireless phone charges, etc.
Installation is quick and easy: Just wrap the DC power cord through the center of the ring filter as many times as you can and reinstall. For best results with long DC power lines, use one at the ring filter at the wall wart end (to prevent the wall wart power supply from using the DC line as an antenna) and another at the DC plug end (to prevent the electronics in the powered device from using the DC power cord as an antenna). Typical installation is shown below:
The filter suppresses RFI in from .1-100 MHz. Inside diameter is 3/4 inch/19 mm.
Since most households and office environments have multiple wall warts we offer the Wall Wart RFI Filter kit in bulk quantity packages.
Known RFI Generators include Roku/Sling-TV power adapter - Interference heard in the AM broadcast band and harmonics. Also many ethernet Cable/DSL modems, cell phone chargers, computer power adapters have the same issue: using the AC or DC side of the power supply as a radiating antenna. RFI solution is to use a linear power supply, change adapters or wall wart ferrite filters