Slip On Coax Feed Line Choke - 1"/25.4mm cable, 1.8-300 MHzProduct DetailsBrand: Palomar EngineersMPN: BA-200Country/Region of Manufacture: USAEffective Frequency Range (MHz): 3-61 (5 bead), 1.8-61 (10, 15 bead)PEP Power Rating (watts): same as coax cable ratingChoking Impedance Range (ohms): 5 bead: 200-900, 10 bead: 400-1400, 15 bead: 600-1700Common Mode Attenuation (db): 5 bead: 9-20 db, 10 bead: 16-24 db, 15 bead: 17-25 dbEstimated Insertion Loss (db): .025Input Connector Type: noneOutput Connector Connector Type: noneGround Connector (Y/N): noneEnclosure Size (LxWxH inches): none1″/25.4mm max Cable Size Chokes
Model BA-200. For use with RG-218 and similar size cables up to 1" OD without connectors installed. Works on all impedance cables, 1.8-300 MHz. Choke outside diameter is 2 inches Requires 9-1/2 inches of cable for 5 bead version, 17" of cable for 10 bead version, and 25" of cable for 15 bead version. Use BA-200-10 or BA-200S-15 for higher choking below 21 MHz. For 10-12 meter frequency use 5 beads up to 15 KW PEP, 10 beads for up to 30 KW PEP and 15 beads for up to 45 KW PEP. We use mix 31 for all chokes. Heat shrink weather proofing kit included. Picture shows 10 bead version.
Rule of thumb suggests you need minimum 5x-10x the coax line impedance for effective choking and the more the better as it will reduce common mode current with higher choking impedance. Select chokes with minimum of 500 ohms at your frequency of interest for best results or upgrade to our CUBE(TM), TUBE(TM), Super Choker(TM) chokes up to 15,000 ohms choking.
Select 10 bead version for 160 meter use, 15 bead version for even higher choking power on lower frequencies. Power rating is same as coax cable used power rating.
Typical choking impedances (BA-58, BA-8, BA-200):
HF 1-61 MHz coax feed line common mode chokes
1″/25.4mm max Cable Size Chokes
Model BA-200. For use with RG-218 and similar size cables up to 1" OD without connectors installed. Works on all impedance cables, 1.8-300 MHz. Choke outside diameter is 2 inches Requires 9-1/2 inches of cable for 5 bead version, 17" of cable for 10 bead version, and 25" of cable for 15 bead version. Use BA-200-10 or BA-200S-15 for higher choking below 21 MHz. For 10-12 meter frequency use 5 beads up to 15 KW PEP, 10 beads for up to 30 KW PEP and 15 beads for up to 45 KW PEP. We use mix 31 for all chokes. Heat shrink weather proofing kit included. Picture shows 10 bead version.
Rule of thumb suggests you need minimum 5x-10x the coax line impedance for effective choking and the more the better as it will reduce common mode current with higher choking impedance. Select chokes with minimum of 500 ohms at your frequency of interest for best results or upgrade to our CUBE(TM), TUBE(TM), Super Choker(TM) chokes up to 15,000 ohms choking.
Select 10 bead version for 160 meter use, 15 bead version for even higher choking power on lower frequencies. Power rating is same as coax cable used power rating.
Typical choking impedances (BA-58, BA-8, BA-200):
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.