EM-25/EM-43 1.8-30MHz Shortwave Choke Coil for RF Feed Lines

EM-25 / EM-43 HF Common-Mode Choke

This 1:1 current choke is designed for 1.8-30 MHz HF feed lines. Installed between the radio and coaxial feeder, it helps suppress common-mode current and reduce RF interference while preserving the intended differential signal path.

Choose the Correct Version

• EM-25: 25 mm ferrite core; rated up to 100 W PEP.
• EM-43: 45 mm ferrite core; larger heat-dissipation area; rated up to 150 W PEP.

Key Specifications

• Frequency range: 1.8-30 MHz
• Configuration: 1:1 current choke / common-mode balun
• Connectors: PL-259 male to SO-239 female
• Primary function: common-mode current and feed-line interference suppression

Typical Applications

• HF transceiver and antenna feed-line installation
• Reducing RF feedback and cable-borne interference
• Portable, field, emergency, and amateur-radio stations
• RF bench checks and antenna-system troubleshooting

Selection Notes

Select EM-25 or EM-43 according to the transmitter power and available installation space. Confirm connector compatibility and keep operation within the listed PEP rating.