Maxi-Core® 20 Baluns and Feedline Chokes reduce or eliminate currents on the outside of your feedline allowing you to hear and to be heard much better. They keep more RFI/BCI out of your antenna and receiver and transfer more of your transmitted signal to the antenna for higher efficiency, the best antenna pattern and maximum performance.

Hear and be heard with DXE Maxi-Core® 20 Baluns and Feedline Chokes!

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The DXE-MC20-1-1T is the 1:1 Current Choke Balun "T for Tuner" model that is chosen for "force feeding" a high SWR antenna or feedline with a tuner. Typically, for higher efficiency, this is the balun to use at the end of any impedance ladder line that is feeding a non-resonant doublet. If higher losses are acceptable, it may be mounted on a coax fed antenna. This model tolerates operation at high SWR on non-resonant multi-band antennas. But, in either case, not all frequencies are available on a single dipole, as this is a choke balun, not a tuner.

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For other antenna and ladder line applications, click Suggested Parts above or click here: Balun/Choke Selection Chart. Descriptions of each Maxi-Core® 20 model appear at the end of this description.

Maxi-Core® 20 Baluns feature 1/4-20 stainless steel hardware and a high-quality, silver-plated SO-239 (UHF female) input connector with a PTFE dielectric. The SO-239 connector limits power handling to 5 kW or less at low SWR, with reduced power handling at elevated SWR.

These baluns and feedline chokes provide very low insertion loss and inherently low SWR. Their weather-resistant NEMA enclosures feature weep holes at all four corners of the bottom side, allowing proper drainage when mounted vertically or horizontally. Optional brackets provide convenient mounting for a variety of antenna installations.

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Optional mounting brackets and plates are available for wire, vertical, Yagi, and beam antennas. See the Suggested Parts tab after clicking “More Detail” on the model of interest. Combination packages that include a balun or choke and mounting bracket are also available.

Suggested mounting options include:

• DXE-WA-BMB

  for wire antennas; allows the addition of a Coax Strain Relief.

• DXE-MC20K-BRKT

  for vertical antennas or for mounting on beam antennas perpendicular to the boom for better performance.

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Signaling a new era of RF performance across the 1.8 to 54 MHz frequency range, DX Engineering Maxi-Core® 20 Baluns and Feedline Chokes handle full-legal-power-plus and provide higher common mode impedance (CMI) across a greater frequency range than competing models and even previous DX Engineering and Comtek models. Years of R&D coupled with major advancements in test equipment and techniques combined with custom ferrite materials have allowed our engineering team to design the DX Engineering Maxi-Core® 20 Baluns and Feedline Chokes.

Common mode impedance (CMI), also known as choking impedance, measures how effectively a balun or feedline choke suppresses unwanted RF currents traveling on the outside of a coaxial cable. These currents can re-radiate signals to the antenna and introduce unwanted signals and noise into the receiver. In some installations, a feedline isolator may also be needed at the transceiver end to suppress noise currents picked up by the feedline before they reach the radio.

Modern testing shows that coiled coax, sometimes called an “ugly balun,” and inexpensive baluns may provide only limited CMI across narrow portions of the HF range. DX Engineering Maxi-Core® 20 Baluns provide much higher CMI across the 160 meter through 6 meter bands.

Maxi-Core® 20 Baluns and Chokes also provide high CMI across the AM Broadcast band and HF/6M spectrum, helping suppress unwanted transmitted and received RFI/BCI currents on the exterior of the feedline shield. Hear and be heard with DXE Maxi-Core® 20 Baluns and Feedline Chokes!

NOTE: Balun polarity markings are important when matching phase on balanced antennas, such as stacked beams used in a phased array. For vertical elements or Inverted-L antennas, connect the positive terminal to the antenna element and the negative terminal to the radial system, counterpoise, ground plane, or ground. For most single balanced-antenna applications, including beams, dipoles, and most wire antennas, balun polarity does not matter.

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Choose the Right Model for Superior Performance:

DXE-MC20-1-1 Maxi-Core® 20 - 1:1 Current Choke Balun - For all HF-6m balanced antennas with a 50 ohm feedpoint, including resonant dipoles, loops, Yagis, beams, etc.

DXE-MC20-FC Maxi-Core® 20 - 1:1 Feedline Choke – This high CMI line isolator is perfect for use in line on 50 ohm coaxial feedlines, at the antenna, at the tower and at the shack end of the feedline.

DXE-MC20-1-1T Maxi-Core® 20 - 1:1 Current Choke Balun – This 1:1 "T" model is for force feeding antennas with a tuner. Use it at the end of ladder line of any impedance or mounted on a coax fed non-resonant antenna. This model tolerates operation at high SWR on non-resonant multi-band antennas. Typically, for higher efficiency, this is the balun to use at the end of any impedance ladder line that is feeding a non-resonant doublet. If higher losses are acceptable, it may be mounted on a coax fed antenna. This model tolerates operation at high SWR on non-resonant multi-band antennas. But, in either case, not all frequencies are available on a single dipole, as this is a choke balun, not a tuner.

DXE-MC20-C4-1 Maxi-Core® 20 - 4:1 Current Choke Balun - For use on antennas with a 200 ohm feedpoint and on any impedance ladder line, especially antenna systems with higher impedance. This model tolerates operation at high SWR on non-resonant multi-band antennas.

DXE-MC20-V4-1 Maxi-Core® 20 - 4:1 Voltage Balun - A 200 ohm to 50 ohm transformer for use on random long-wire and OCF antenna applications. This true voltage balun is intentionally designed with low CMI for antennas that need a transformer without RF choking for easier antenna tuner operation. This model tolerates moderately elevated SWR.