LDG RU-1:1 Unun Common-Mode RF Choke, 1.8–30 MHz, 200W PEP, SO-239

The LDG RU-1:1 is a 1:1 Unun functioning as a common-mode RF choke — designed to remove unwanted RF from the outer shield of your coax cable. Unlike the 4:1 and 9:1 variants, the 1:1 performs no impedance transformation; instead it suppresses common-mode currents that can cause RF interference, erratic SWR readings, and RF in the shack. Particularly useful on short coax runs and with non-resonant antennas.

Features SO-239 sockets on both input and output for straightforward in-line installation. Rated at 200W PEP and covering 1.8–30 MHz across all HF amateur bands from 160m to 10m. Weatherproof-ready for permanent outdoor use.

Key Features

• Configuration: 1:1 Unun (common-mode RF choke)
• Removes RF from coax shield — reduces shack interference and erratic SWR
• Connectors: SO-239 input and output
• Frequency coverage: 1.8–30 MHz (160m–10m)
• Power rating: 200W PEP
• Easy to weatherproof for outdoor installation

Technical Specifications

• Configuration: 1:1 Unun
• Connectors: SO-239 (input and output)
• Frequency: 1.8–30 MHz
• Max power: 200W PEP