CMC-230-5K 2-30MHz


Common Mode Filter Choke / Noise Suppressor / Line Isolator –DISCONTINUED

The common-mode filter or choke may be one of the best-kept secrets…

  • Covers 2-30MHz
  • Power 5kW *ICAS
  • Common-mode attenuation: ~40dB
  • Choking Impedance 7000-12000 Ohms

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Available on backorder

SKU: CMC-230-5K Category: Tag:


CMC-230-5K Common Mode Filter Choke / Noise Suppressor / RF Isolator

The best Common Mode Filter Choke for 2-30 MHz on the market. There is no such product available matching the performance of CMC-230-5K.

  • Perfect to cure RFI/EMI problems.
  • Great noise suppressor!
  • Common-mode attenuation is up to 40dB max.

It is a cure for noisy locations, reduce the noise floor of your receiver by several S-units instantly.  If you have unbalanced antennas such as OCF dipole or your antennas close to your home, adding one CMC230-5K will greatly reduce RF Interference problems on your equipment and 120/220V wiring inside your home. We do not claim “one size fits all” but actually, we design, measure and make such products. Our CMC-230-5K has huge Resistive values of Common Mode Choking Impedance over almost 30MHz or whole HF spectrum, click the chart on the side for actual measurement data.

Unlike other companies, we do not claim unrealistic impedance values or frequency coverage. Most important, the value of CMC-230-5K Common Mode Choking Impedance and its Resistive (Rs) part is always higher than the Reactive part (Xs) over the working bandwidth. This parameter, Rs>Xs ensure that our CMC will NOT increase common mode currents as could with inferior coaxial cable chokes.

Only chokes with Resistive (Rs>Xs) CMI- Common Mode Impedance stops and dissipate unwanted RF or noise coming to your equipment for sure.

CMC-230-5K Features:

  • Two cascaded chokes (2) on four (4) large 2.4″ (61mm) Ferrite cores for maximum Choking Impedance and bandwidth.
  • SO-239 PTFE (Teflon®) Connectors which produce no impedance bump but the continuity of coaxial cable where the choke is inserted, it helps minimize leakage of RF in multi/contest stations setups.
  • PTFE (Teflon®) insulated coaxial cable is used, it can handle a lot more than legal power (1500W) in the USA. Rated at 5kW ICAS.
  • Enclosure with mounting flanges for easy installation inside or outside the station setup. It has been tested for UV (Ultra Violet) exposure for the past eight years with no impact on the material.


  • Zmag-Impedance Magnitude     
  • Rs-Series Choking Resistance      
  • Xs-Series Choking Reactance


*ICAS = Intermittent Commercial and Amateur Service

Additional information

Common-mode attenuation:

~40dB maximum

Frequency Range:

1.8-30 MHz

Maximum Power:

5kW I.C.A.S


PTFE/silver SO-239 connector


(L x W x H) (in / mm) 6.00 x 4.38 x 1.97 in. / 152.40 x 111.25 x 50.04 mm


1.85 lb (0.84 kg)