Availability
Baluns, Ununs and RF Chokes
REZ Antenna Systems CM7 Common Mode Feedline Chokes
REZ Antenna Systems CM7 Common Mode Feedline Chokes are inline 1:1 common mode feedline chokes, consisting of seven mix-31 ferrite beads and RG223/U double shield coax. Proudly made in the USA, the compact and streamlined CM7 was designed to solve some of the most common issues that can negatively impact antenna system tuning and performance. For instance, common mode current carried on the outside of a coaxial cable can cause unwanted RF traveling back to your operating position, causing many issues. Another common issue is that the coax will become part of the antenna system and begin radiating RF. In most cases this is undesirable. Simply install the CM7 at the feed point of your antenna and attach your exiting coaxial cable to the opposite end. The CM7 can be used with many popular antenna types, such as EFHW, dipoles, random wires and verticals, to improve tuning consistency and antenna performance. Many antennas require the use of a 1:1 choke to isolate the coaxial cable from the antenna system for proper performance. Why not improve the performance of your antenna system? Order a REZ Antenna Systems CM7 Common Mode Choke from DX Engineering.
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$69.99
COMTEK CFC-50X Common Mode Feedline Chokes
COMTEK CFC-50X Common Mode Feedline Chokes are designed to suppress unwanted RF currents on the outside of the shield on coaxial feedlines. These 1:1 inline coaxial feedline chokes are built with fifteen Mix-31 ferrite beads on premium DX Engineering RG-8X coaxial cable, offering improved performance for a wide variety of antenna systems. COM-CFC-50X Key Benefits: • Provides Effective Shield RF Current Suppression from 1.8 to 54 MHz, helping eliminate common mode currents that cause RF feedback and noise inside the feedline. • Consistent and balanced pattern across frequency range: Excellent RF choking isolating the feedpoint prevents current imbalance, which preserves radiation pattern and antenna performance.
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$59.99
DX Engineering LPFC-BNC Low Power Feedline Chokes
DX Engineering LPFC-BNC Low Power Feedline Chokes are intended to be placed in line with coaxial cable fed antennas and equipment used for portable operations, including POTA and SOTA activations. The DXE-LPFC-BNC coax wound toroid achieves an amazing common mode impedance (CMI) curve, with an RF choking capability that far exceeds the CMI of 'a-few-beads-on-coax' product that is offered by other suppliers. Actually, these "Low Power" Feedline Chokes can be used in any station that runs less than 250 watts SSB, 100 watts CW or Digital. ________________________________________ DX Engineering Low Power Feedline Chokes features and benefits: - A unique, lightweight form, with clear heat shrink over the choke* - Light enough to hang inline at the feedpoint of any portable HF antenna. - BNC female connectors for easy connection to portable antennas and gear. - Much higher CMI that other portable, low power chokes, especially across the 40 through 6 meter bands. - Frequency range of 1.8 through 54MHz. - RF Power Handling up to 250 watts PEP SSB, 100 watts CW and Digital (at SWR <2:1). - Recommended for general use to isolate either end of a coaxial cable. * Not intended for permanent outdoor use unless mounted inside a weatherproof enclosure. ________________________________________ These chokes are ideal for use at any HF transceiver or receiver antenna connection, portable, mobile or base. In most cases, DXE-LPFC-BNC prevents RFI, stops stray RF and noise on the feedline from getting into the receiver that would cover up weak signals, and improves efficiency of the antenna system. For any station, including POTA and SOTA, mobile and base, DX Engineering Low Power Feedline Chokes keep the RF controlled.
Not Yet Reviewed
$59.99
PackTenna Mini In-Line RF Feedline Chokes
PackTenna Mini In-Line RF Feedline Chokes are designed to suppress RF interference caused by common mode current flowing from the antenna feed point back to the radio. This type of current can disrupt radio performance and affect nearby equipment. In-line chokes are recommended for all end-fed antennas when operating above 20 watts. While you may not experience issues immediately, RF interference can occur as you increase power, change bands, adjust coax length, or reposition the antenna.
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$75.00
DX Engineering TWIG QRP 4:1 Current Baluns
The DXE-TWIG-4-1C QRP Current Balun is designed to be used as the feedpoint of a very low power (QRP) Off Center Fed dipole (OCF) antenna. Ideal for use during outdoor adventures such as POTA® or SOTATM, or any portable operation. The TWIG-4-1C incorporates a 4:1 transformer to convert the OCF antenna impedance of 200-ohms to the desired 50-ohms to match the coaxial cable feedline. It also has a 1:1 feedline choke, to prevent current imbalance, detuning, and to help prevent the addition of unwanted noise. The connector is a BNC female and mates with the recommended coax and most low power (QRP) transceivers. When properly installed and the element wire is properly tuned, you should not need an external tuner. This reduces the need to bring more equipment than is necessary or a portable operation and provides higher efficiency of your output signal and instant band changes. The antenna shown in this manual was designed and tested using the optional 24 AWG wire such as CEW-VIZ24-YEL100 stranded copper, PVC insulated, high visibility yellow antenna wire. The BNC connectors coax cable is recommended to be at least 25 to 35 feet in length. The antenna can be installed in different configurations of wire lengths for various band selections. For example, a very common TWIG QRP OCF for 40, 20, 15 and 10 meters has one 57 ft. dipole wire and the other wire is 12 ft. See the chart in the Instruction Manual linked below for details. This is a low power (QRP) antenna system balun which handles only 25 Watts on SSB, 10 Watts on CW and 5 Watts on digital mode when antenna SWR less than 2:1, without the use of an antenna tuner.
Not Yet Reviewed
$69.99
Elecraft BL2 Switchable Balun Kit
Redesigned for higher power operation, Elecraft's BL2 Switchable Balun Kit provides two ratios, 4:1 and 1:1, with high efficiency, simplicity, and durability in a compact package. The kits are versatile and compact enough for a variety of matching applications. Shipped as an unassembled kit for custom builds and custom enclosures. Elecraft BL2 features and specs include: * 500 kHz to 55 MHz functionality * Rated to 250 W PEP, 100 watts CW * Rugged slide switch for switchable ratios * Compact size: 1.5 in. wide and 3.0 in. long * Lightweight * Screw terminals for balanced output and ground * Unique winding results in SWR of less than 1.2:1
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$76.95
DX Engineering Bead Choke Standoff Kits
DX Engineering Bead Choke Standoff Kits bring a practical solution to a serious problem when ferrite chokes are placed directly onto the metal boom at the feedpoint of beam antennas. A number of Amateur Radio operators and antenna engineers have known for years about the superior choking function of many ferrite toroids beads placed directly on the coaxial cable, as compared to standard feedpoint baluns. A more recent revelation is that the proximity of ferrite beads on coax taped to the aluminum boom of the antenna drastically reduces their effectiveness. DX Engineering Bead Choke Standoff Kits are mounting systems, made of fiberglass or acetyl standoff rods (color varies), PVC carriers and stainless steel hardware, available in four versions. Two sizes of PVC cradle tubes handle two different types of RF bead chokes; 3/4 inch outside diameter (OD) ferrite beads on RG-400 size cable, and 1 inch OD ferrite beads on RG-213 size 0.405 in. coax cable. Each are offered with two different boom size clamps, 2 inch OD and 3 inch OD. Bead Choke Standoff Kits simply hold an RF bead choke and feedline 4 inches away from the metal beam antenna boom (or 4 inches away from the metal mast for a dipole). They maintain the optimal choking performance of ferrite beads on coax. Using DX Engineering Bead Choke Standoff Kits, ferrite bead chokes function at peak performance for these key results: • Prevent feedline radiation of RF • Preserve current balance for proper beam antenna pattern • Prevent feedline shield exterior collected noise and signals from entering the antenna and interior of the feedline, resulting in lower noise floor and enhanced reception The absolute superiority of RF chokes made of many beads on the feedline, over the traditional enclosure balun, is becoming better understood in Amateur Radio. They achieve the best possible RF isolation of the feedline from the antenna and provide completely balanced currents at the feedpoint. Plus, they provide quieter reception with reduction of common-mode noise. Keeping Bead RF Chokes away from metal preserves the optimal function of this method of antenna feedpoint current balance and isolation. This mechanical requirement is simple and practical with DX Engineering Bead Choke Standoff Kits.
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$52.79
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$65.99
EAntenna Replacement Baluns
Need to get your Delta antenna back online? EAntenna's Replacement Baluns are your answer. They're manufactured from the same quality materials to the same specifications as the original. Direct replacements for specific models and variations are available; please confirm application before ordering. Restore your antenna to full capacity with EAntenna's Replacement Baluns!
Not Yet Reviewed
$85.99