DX Engineering DXE-MC20-FC Balun and Choke Selection Chart

®

DX Engineering Maxi-Core

20

Baluns & Feedline Chokes

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.

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, is a measure of how well a Balun or Feedline Choke reduces
exterior RF currents traveling through it and on the outside of the coaxial cable. Currents that travel on the outside of the coax re­radiate signals directly to your antenna and then travel to your receiver. Even with a Feedline Isolator (Choke) or Balun at the antenna
end of the transmission line, many times a Feedline Isolator is necessary at the transceiver side in order to squelch the noise currents
picked up by the feedline on the way to the radio.

Modern testing methods clearly show that coiled coax, sometimes known as an “ugly balun,” and inexpensive baluns provide minimal
CMI over just narrow frequency segments of the HF range.

Maxi-Core® 20 Baluns and Feedline Chokes have high CMI across the AM Broadcast band and the HF/6M spectrum, which is
essential to provide sufficient suppression of unwanted transmitted and received RFI/BCI current on the feedline shield exterior.

Optional mounting brackets are available for use on wire antennas or for verticals, Yagi and beam antennas. See the Suggested Parts
tab after clicking "More Detail" on the DX Engineering web site on the model Balun/Choke of interest. Each model listing provides
additional specific information. Combination packages that include balun or choke and bracket are also available.
Hear and be heard with DX Engineering Maxi-Core® 20 Baluns and Feedline Chokes!

Features and benefits of Maxi-Core® 20 Baluns and Feedline Chokes:

 Performance at the highest levels of efficiency in transmit or receive applications
 Reduction or elimination of transmit RFI and receive noise
 Currents on the feedline or antenna are forced equal for maximum efficiency and more symmetrical antenna patterns
 Weather resistant NEMA enclosure with convenient mounting holes
 Four weep holes to help eliminate internal moisture
 High Quality PTFE dielectric, Silver Plated SO-239 Connector
 1/4-20 Stainless Steel Hardware

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-MC20-1-1T 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. Tolerates elevated SWR.

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, tower or shack end of the feedline.

Antenna Types

Suggested Balun/Choke

MC20-1-1

MC20-1-1T

MC20-C4-1

DXE-MC20-V4-1

MC20-FC

Dipole, coax fed, resonant

X X X

Dipole, double extended

X X

Dipole, folded, 300 ohm feed

X X

Dipole, folded, coax fed, resonant

X X

Dipole, folded, multi-wire

X

Dipole, folded, non-resonant

X X X

Dipole, folded, two-wire

X X

Dipole, inverted “V”, non-resonant

X X

Dipole, inverted “V”, resonant

X X

Dipole, ladder line fed, non-resonant

X X

Dipole, linear load, ladder line fed

X X

Dipole, long, non-resonant

X X

Dipole, multi-band resonant

X X

Dipole, off-center fed (80/20 OCF)

X X

Dipole, snake type, ladder line fed

X X

Dipole, trap

X X X

Doublet, multi-band, ladder line fed

X X

Horizontal “V” doublet

X

Inverted “V”, coax fed, resonant

X X

Log periodic, 150-250 ohm feedpoint

X

Log periodic, 50 ohm, direct coax feed

X

Long wire with ground system

X X

Loop, horizontal, coax fed

X

Loop, horizontal, non-resonant

X X

Loop, vertical, non-resonant

X

Loop, vertical, resonant, coax feed

X X X

Multi-band, ladder line fed

X X

Multi-band, remote balun

X X

Windom, balanced feed

X

Windom, conventional single wire

X

Yagi, 200 ohm feedpoint (KT-34, X-7)

X

Yagi, 50 ohm, direct coax feed

X X

Yagi, gamma matched

X X

Yagi, hairpin/beta matched

X X X

Yagi, trap tri-bander

X X X

Warranty

All products manufactured by DX Engineering are warranted to be free from defects in material and workmanship for a period of one (1) year from date of shipment. DX Engineering’s sole obligation under these
warranties shall be to issue credit, repair or replace any item or part thereof which is proved to be other than as warranted; no allowance shall be made for any labor charges of Buyer for replacement of parts,
adjustment or repairs, or any other work, unless such charges are authorized in advance by DX Engineering. If DX Engineering’s products are claimed to be defective in material or workmanship, DX Engineering
shall, upon prompt notice thereof, issue shipping instructions for return to DX Engineering (transportation-charges prepaid by Buyer). Every such claim for breach of these warranties shall be deemed to be
waived by Buyer unless made in writing. The above warranties shall not extend to any products or parts thereof which have been subjected to any misuse or neglect, damaged by accident, rendered defective by
reason of improper installation, damaged from severe weather including floods, or abnormal environmental conditions such as prolonged exposure to corrosives or power surges, or by the performance of repairs
or alterations outside of our plant, and shall not apply to any goods or parts thereof furnished by Buyer or acquired from others at Buyer’s specifications. In addition, DX Engineering’s warranties do not extend to
other equipment and parts manufactured by others except to the extent of the original manufacturer’s warranty to DX Engineering. The obligations under the foregoing warranties are limited to the precise terms
thereof. These warranties provide exclusive remedies, expressly in lieu of all other remedies including claims for special or consequential damages. SELLER NEITHER MAKES NOR ASSUMES ANY OTHER
WARRANTY WHATSOEVER, WHETHER EXPRESS, STATUTORY, OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS, AND NO PERSON IS AUTHORIZED TO ASSUME
FOR DX ENGINEERING ANY OBLIGATION OR LIABILITY NOT STRICTLY IN ACCORDANCE WITH THE FOREGOING.

©DX Engineering 2020

DX Engineering®, DXE®, DX Engineering, Inc.®, Hot Rodz®, Maxi-Core®, DX Engineering THUNDERBOLT®, DX Engineering Yagi Mechanical®, EZ-BUILD®, TELREX®, Gorilla Grip® Stainless Steel Boom
Clamps, Butternut®, SkyHawk™, SkyLark™, SecureMount™, OMNI-TILT™, RF-PRO-1B®, AFHD-4® are trademarks of PDS Electronics, Inc. No license to use or reproduce any of these trademarks or other
trademarks is given or implied. All other brands and product names are the trademarks of their respective owners.

Specifications subject to change without notice.

Phone: [phone] - Tech Support and International: 330-562-3200 - Fax: [phone]

Note: A balun mounting bracket is required to take the strain off of the balun connections.

DX Engineering has a variety of balun mounting brackets available.

1200 Southeast Ave. - Tallmadge, OH 44278 USA

E-mail: [e-mail]

©DX Engineering 2020

DXE Baluns-Rev 1b