(2 customer reviews)


Common Mode Choke / Noise Suppressor / Line Isolator

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

  • Covers 3-30MHz
  • Power 5kW *ICAS
  • Choking Impedance 4600-6800 Ohms

Out of stock

SKU: CMC-330-5K Category: Tag:


CMC-330-5K Common Mode Choke / Noise Suppressor / RF Isolator

CMC-330-5K-webThe best Common Mode Choke for 3-30MHz on the market. There is no similar product available matching the performance of CMC-330-5K. Perfect to cure RFI/EMI problems. Great noise suppressor! 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 CMC-330-5K 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-330-5K has huge Resistive values of Common Mode Choking Impedance from 3 – 30MHz, 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-330-5K 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-330-5K Features:

  • Two 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, helps minimize leakage of RF in multi/contest stations setups.
  •  PTFE (Teflon) insulated coaxial cable used, reduces RF leakage and 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 material.


Frq.(MHz) Zmag(Ohms) Rs(Ohms) Xs(Ohms)
 1.85  2900    
3.75 4600 3500 3100
7.15 6000 5800 1800
10.1 6400 4600 500
14.15 6800 6500 -1100
18.1 6400 6000 -2400
21.2 6200 5400 -3100
24.9 5800 4500 3600
28.3 5400 3900 -3700
  • Zmag-Impedance Magnitude     
  • Rs-Series Choking Resistance      
  • Xs-Series Choking Reactance

CMC-330-5K-CMI- Common Mode Impedance

CMC-330-5K-CMI- Common Mode Impedance

*ICAS = Intermittent Commercial and Amateur Service

Additional information

Product Data


Impedance data

data, data2, data3

2 reviews for CMC-330-5K

  1. Frank EA6ABK

    Hi Dany….
    with CMC-330-5K the problem of RF is over… thank you very much for your advice …. Merry Christmas !!

  2. chuck

    I’ve had one of these for several years now. Not one issue and the VSWR and load impedance does not change going through these. I’ve been using another company’s product and I don’t think it can handle the power as well as not being well behaved in the VSWR/impedance arena so I’m going to order another CMC330-5k and toss the other device. Thanks guys. Great product.

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