50:200 ohm (4:1) Dual Core Current Balun Kit, 1-55 MHz, 1500 watts PEP, for OCF, Loop, Ladder Line AntennasProduct DetailsMPN: BA-4-1000DCType: balun or ununInput ohms/Output ohms: 50 in, 200 outFrequency Range < 2:1 SWR (MHz): 1-55PEP Power Rating (watts): 1500 Watts PEPAntenna Compatability: Balun: Ladder line to coax interfacePurpose. Model BA-4-1500DC is a 4:1 dual core balun kit (assembly required from parts supplied) used to translate a 50 ohm input up to 200 ohms at RF power levels up to 1000 watts when used with a matched load. It provides conversion from unbalanced coax to balanced ladder line/antenna feed point and gives a 4:1 impedance step-up to reduce SWR on the coax. Place at the junction of the balanced line and the coax to convert from balanced line to unbalanced coax.
KIT Contents. The kit consists of a 2 ferrite toroidal cores, two colors of insulated wire, a SO-239 UHF connector with stainless steel hardware, and an instruction manual.
Assembly time: About 1 hour, illustrated manual included with purchase.
Radio Club idea:
Buy 10 for a club do it yourself construction project - you can learn something and also build an end fed antenna (just add wire).
Product picture shows assembled item of all components in kit.
NOTE: for higher power and a true current balanced 4:1, use our BA-4-1500DC dual core 4;1 balun kit
HF 1-61 MHz coax feed line common mode chokes
Purpose. Model BA-4-1500DC is a 4:1 dual core balun kit (assembly required from parts supplied) used to translate a 50 ohm input up to 200 ohms at RF power levels up to 1000 watts when used with a matched load. It provides conversion from unbalanced coax to balanced ladder line/antenna feed point and gives a 4:1 impedance step-up to reduce SWR on the coax. Place at the junction of the balanced line and the coax to convert from balanced line to unbalanced coax.
KIT Contents. The kit consists of a 2 ferrite toroidal cores, two colors of insulated wire, a SO-239 UHF connector with stainless steel hardware, and an instruction manual.
Assembly time: About 1 hour, illustrated manual included with purchase.
Radio Club idea:
Buy 10 for a club do it yourself construction project - you can learn something and also build an end fed antenna (just add wire).
Product picture shows assembled item of all components in kit.
NOTE: for higher power and a true current balanced 4:1, use our BA-4-1500DC dual core 4;1 balun kit
1:1 feed line Chokes (also known as feed line current chokes, common mode chokes, line isolators, current mode chokes, and 1:1 baluns/ununs) are available in kit form or assembled form in a weatherproof Current Unun and Balun Enclosure which we call a CUBE™. All 1:1 chokes are ferrite based and are designed for 50 ohm coaxial cable input and 50 ohm output. 1:1 Ferrite toroidal or bead chokes have a higher choking impedance than our popular Sleeve Chokes and various models are available for specific frequency ranges and power levels.
1:1 Chokes are useful for choking common mode currents that may flow on the exterior of the coax cable shield while allowing the signals on the interior of the shield and the center conductor to flow unaffected and keeping the common mode current on the antenna. They isolate the coax shield and prevent it from becoming part of the antenna system.
1:1 Chokes are useful between balanced lines for center fed dipoles at their fundamental frequency (468/f (MHz), beam antennas with a 50 ohm balanced driven element, G5RV, loops, yagis, NVIS antennas, mobile installations, portable antennas and anywhere common mode current (or RFI) is a problem. They are also helpful between transmitter and linear amplifier or between linear amp and antenna tuner or as isolation chokes where higher choking impedance is needed (in the range of 2K-7K ohms).
1:1 Chokes are also very useful as feed line current chokes at the “radio end” of the antenna (we call them coax noise filters) where they choke/filter common mode current induced onto the coax shield from radiated waves (from your antenna, and other sources such as DSL routers, computer devices, plasma TVs, etc. originating in your house or your neighbor’s house). For RFI issues see RFI/EMI Solutions for general use or for specific radios and devices.
For best results we recommend a 1:1 choke at the “antenna end” of the coax and a coax noise filter at the “radio end” of the coax. (A side benefit is a reduction in noise level caused by common mode currents). 1:1 chokes are also available as Sleeve Chokes (Slip on or Snap on) for ease of installation and light weight on the antenna.