Availability
22 Results Found For "in-line"
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
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
COMTEK Current Feedline Chokes
The updated COMTEK CFC-50A 50 ohm Feedline Chokes consist of 75 heavy-duty mix-31 RF choke beads on a length of RG400 PTFE coax terminated at both ends with silver-plated PTFE PL-259/UHF male connectors and the correct length of heat-shrink tubing. COMTEK Current Feedline Chokes ensure that stray RF does not flow on the outside shield of your feedlines. They are typically installed at the antenna feedpoint connection. They may also be used where a long run of feedline leaves a remote antenna switch or a tower. They are also very effective at the shack end of a long run of on-the-ground or above-ground coaxial feedline, to block unwanted RF signals and noise picked up on the shield. These chokes provide excellent common mode impedance and handle up to 5 kW from 1.8 to 54 MHz. These chokes are assembled except for the tubing needs to be installed and heat-shrinked after the choke is positioned as it will be installed.
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$131.49
Momobeam RFC-LI 1kW Single Core Line Isolator RF Choke Baluns
Momobeam RFC-LI 1kW Single Core Line Isolator RF Choke Baluns are efficient broadband common mode current chokes designed to ensure proper current balance and clean transitions between balanced resonant antennas—such as dipoles and Yagi antennas—and unbalanced coaxial feed lines. By delivering excellent suppression of unwanted common mode current across a wide frequency range, these RF chokes help maintain optimal antenna performance and protect sensitive station equipment. Common mode currents can cause a variety of station problems, including elevated receiver noise levels, inaccurate SWR measurements, and interference affecting nearby electronic devices or equipment within the shack. The RFC LI effectively prevents these issues by stopping common mode current from traveling on the outside of the coaxial shield, ensuring cleaner transmit and receive performance under all operating conditions.
Not Yet Reviewed
$144.99
Momobeam RFC-LI 2kW Dual Core Line Isolator RF Choke Baluns
Momobeam RFC-LI 2kW Dual Core Line Isolator RF Choke Baluns are efficient broadband common mode current chokes designed to ensure proper current balance and clean transitions between balanced resonant antennas—such as dipoles and Yagi antennas—and unbalanced coaxial feed lines. By delivering excellent suppression of unwanted common mode current across a wide frequency range, these RF chokes help maintain optimal antenna performance and protect sensitive station equipment. Common mode currents can cause a variety of station problems, including elevated receiver noise levels, inaccurate SWR measurements, and interference affecting nearby electronic devices or equipment within the shack. The RFC LI effectively prevents these issues by stopping common mode current from traveling on the outside of the coaxial shield, ensuring cleaner transmit and receive performance under all operating conditions.
Not Yet Reviewed
$180.99
Momobeam RFC-LI 4kW Dual Big Core Line Isolator RF Choke Baluns
Momobeam RFC-LI 2kW Dual Core Line Isolator RF Choke Baluns are efficient broadband common mode current chokes designed to ensure proper current balance and clean transitions between balanced resonant antennas—such as dipoles and Yagi antennas—and unbalanced coaxial feed lines. By delivering excellent suppression of unwanted common mode current across a wide frequency range, these RF chokes help maintain optimal antenna performance and protect sensitive station equipment. Common mode currents can cause a variety of station problems, including elevated receiver noise levels, inaccurate SWR measurements, and interference affecting nearby electronic devices or equipment within the shack. The RFC LI effectively prevents these issues by stopping common mode current from traveling on the outside of the coaxial shield, ensuring cleaner transmit and receive performance under all operating conditions.
Not Yet Reviewed
$229.99
DX Engineering Maxi-Core® 20 Baluns and Feedline Chokes
The present-day DX Engineering was launched in the year 2000. To celebrate our 20th Anniversary in the year 2020 we have developed a new line of Baluns and Feedline Chokes. Introducing DX Engineering "Maxi-Core® 20" Baluns and Feedline Chokes. They 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. Maxi-Core® 20 Baluns and 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. Hear and be heard with DXE Maxi-Core® 20 Baluns and Feedline Chokes. Choose superior performance from these models: * 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, tower or 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. * DXE-MC20-C4-1 Maxi-Core® 20 - 4:1 Current Choke Balun is for use on antennas with a 200 ohm feedpoint and at the end of any impedance ladder line, especially on 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 is 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 and it tolerates elevated SWR. Maxi-Core® 20 Baluns and Feedline Chokes are built into a convenient weather resistant NEMA enclosure that is mounted easily with optional brackets. They feature 1/4-20 stainless steel hardware and a high quality silver-plated PTFE dielectric SO-239 (UHF female) input connector. The SO-239 connector limits power handling to 5 kW at low SWR and reduced power at elevated SWR. These baluns and the feedline choke exhibit very low insertion loss and inherently low SWR. 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 model of interest. Combination packages that include balun or choke and mounting bracket are also available.
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$141.99
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$169.99
LDG Electronics RU-9:1 Unun
LDG Electronics RU-9:1 Unun was designed to allow easy interface of random length vertical and end fed antennas to the LDG line of Automatic Antenna Tuners. This 200 watt Unun also operates as a standalone, meaning that it does not necessarily require a tuner for use on a certain antenna. It may be used with many of your antenna projects where a 4:1 Unun is typically recommended. This model is small and easy to weatherproof for use in the elements. LDG RU-9:1 Unun specs: * Ratio: 9:1 * Frequency coverage: 1.8 to 30 MHz. * Power range: Up to 200 watts PEP * Enclosure dimensions (WHD): 2.5 x 5 x 1.25 in. * Weight: 6 oz.
( 99 )
$39.99
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
LDG Electronics 1:1 Current Baluns
LDG Electronics 1:1 Current Baluns were designed to allow for the easy interface of ladder line antennas and long wires with the LDG line of automatic antenna tuners. * Configuration: 1:1 Current Balun * Frequency Coverage: 1.8 to 30 MHz. * Power Range: 100W continuous or 200 watts PEP * Easy to weatherproof * Enclosure size: 5 x 2.5 x 1.25 in. * Weight: 6 oz. (including enclosure) These baluns operate "stand alone"; thus, they do not require an LDG tuner. They may be used with any of your longwire, random wire, or ladder line antenna projects. For low power operation it's hard to beat the value in LDG Electronics 1:1 Current Baluns from DX Engineering!
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$39.99
Chelegance JBalun-915 1:1 Feedline Chokes
Chelegance JBalun-915 1:1 Feedline Chokes are 1:1 ferrite chokes designed for inline use with 50-Ohm coaxial cable. Engineered to enhance performance in both stationary and portable Amateur Radio stations, it operates effectively from 1.8 to 30MHz and supports up to 500W PEP.
Not Yet Reviewed
$152.99
LDG Electronics 4:1 Voltage Baluns
LDG Electronics 4:1 voltage baluns were designed to allow for the easy interface of ladder line antennas and long wires with the LDG line of automatic antenna tuners. * Configuration: 4:1 Voltage Balun * Frequency Coverage: 1.8 to 30 MHz * Power Range: 100 W continuous or 200 watts PEP * Easy to weatherproof * Enclosure size: 5 x 2.5 x 1.25 in. * Weight: 6 oz. (enclosure weight included) These baluns operate "stand alone"; thus, they do not require an LDG tuner. They may be used with any of your long, random, or ladder line or other antenna projects.
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$39.99
DX Engineering Maxi-Core® 20 Feedline Choke and Mount Kits
DX Engineering Maxi-Core® 20 Feedline Choke and Mount Kits, DXE-MC20-FCM, provide current balance and feedline isolation on coaxial cables for all types of HF through 6 meter antennas including verticals, rotatable dipoles, directional beams and Yagi antennas. Intended for 50 ohm feedlines operated at low SWR, this combination of mounting plate bracket and effective 50 ohm RF choke handles full-legal-power-plus and provides higher common mode impedance (CMI) across a greater frequency range than competing feedline choke and line isolators and previous DX Engineering and Comtek models. High CMI across the AM Broadcast band and the HF/6M spectrum is essential to provide sufficient suppression of unwanted transmitted and received RFI/BCI current on the feedline shield exterior. With less noise and interference you will hear and be heard using a DX Engineering Maxi-Core® 20 Feedline Choke and Mount Kits. DX Engineering Maxi-Core® 20 Feedline Choke and Mount Kits bring new parts together to work on many types of antennas. They provide improved RF isolation and current balance at either end of the feedline and at the feedpoint of a vertical, a beam, rotatable dipole or other antenna feedline. This is a unique perpendicular choke mount that allows a beneficial separation between the ferrite of the choke and the antenna boom or mast, resulting in improved choking performance compared to a choke mounted on metal. The UV black high-strength polymer mounting plate provides additional isolation and holes for different mounting positions for the choke, horizontal or vertical. Stainless steel hardware is included to attach the plate to the stainless steel mounting bracket, which has laser cut holes for one of five optional DX Engineering Saddle Clamps to cover mast or boom sizes from 1 to 2 in. and 2.375 to 3 in. Click "More Detail" for additional information and click Suggested Parts for required optional items including one saddle clamp to fit your mast or boom and coaxial cable assemblies. Maxi-Core® 20 Feedline Chokes features high quality silver-plated PTFE dielectric SO-239 (UHF female) connectors. The SO-239 connector limits power handling to 5 kW or less at low SWR and reduced power at elevated SWR. These feedline chokes exhibit very low insertion loss and inherently low SWR. They are built into a convenient weather resistant NEMA enclosure with weep holes at all four corners of the "bottom" side of the enclosure, to vent properly when mounted vertically or horizontally for all types of antennas. Make your antenna play to its potential; reduce RFI and improve reception with DX Engineering Maxi-Core® 20 Feedline Choke and Mount Kits.
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$207.98
DX Engineering Dual Impedance Antenna Transformers
DX Engineering Dual Impedance Antenna Transformers are dual ratio UNUN (unbalanced to unbalanced line) transformers. They're great for coupling your 50 ohm coax to an antenna with a feed point impedance of either 25 or 12.5 ohms, typically found at HF mobile antennas. DX Engineering Dual Impedance Antenna Transformers are ideal for antennas that have been enhanced with a Hot Rodz capacity hat. These transformers are housed in an aluminum enclosure and use silver plated PTFE SO-239 connectors. Many mobile HF antennas are naturally between 10 ohms and 36 ohms at resonance. With 10 ohms at a 50 ohm feed point the resulting SWR is 5:1! Likewise, 36 ohms yields a 1.4:1 SWR. Matching at 1.4:1 isn't too bad, but 5:1 is definitely an issue. DX Engineering MM-1 Dual Impedance Antenna Transformers are ideal for adjusting the impedance mismatch in your HF mobile! When the natural resonant impedance of the antenna is at 30 ohms or below, the MM-1 mobile unun can provide the needed match. With a 50 ohm input, it provides a 25 ohm port and a 12.5 ohm port to facilitate mobile HF matching. Let's say that your antenna analyzer indicates a resonant antenna impedance of 22 ohms. Your SWR without an MM-1 would be 50/22 or 2.27:1. That's enough to cause considerable power rollback in most modern HF rigs. Using the MM-1 25 ohm port, your SWR would be 25/22, or 1.14:1. That's a very significant improvement! Many hams are using antenna analyzers to adjust mobile HF antennas. When a mismatch is indicated at resonance, a DX Engineering MM-1 Unun can solve the problem! Power handling capability depends on the match: * Using the 25 ohm to 50 ohm port, with SWR below 2:1 on the 50 ohm side, -- 750 watts PEP * Using the 12.5 ohm to 50 ohm port, with SWR below 2:1 on the 50 ohm side, -- 500 watts PEP Note: Whenever the DX Engineering "Documentation" tab is available, please look at the associated files for additional product information. Antenna analyzers are becoming more common. Buy or borrow one to check the impedance of your mobile antennas. Then get DX Engineering Dual Impedance Antenna Transformers to get the best match and highest efficiency you can!
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$184.99
The Radio Source TheMATCHBOX Broadband Matching Transformer
The Radio Source TheMATCHBOX Broadband Matching Transformer is a multi-tap transmission-line transformer designed to raise the inherently low feed-point impedance of electrically short end-fed antennas to a value suitable for direct connection to 50-ohm coaxial cable. Unlike conventional transformers that provide optimal performance primarily above 1 MHz, TheMATCHBOX delivers efficient operation down to 100 kHz using a manganese-zinc (MnZn) toroid core, minimizing loss while maintaining a low standing wave ratio. Because the feed-point impedance of electrically short end-fed antennas is influenced by antenna length, ground conductivity, and ground system quality, TheMATCHBOX is field-configurable with eight impedance transformation ratios. This flexibility allows it to match antennas with feed-point impedances ranging from 3 to 37 ohms to a standard 50-ohm coaxial feed line. Designed for permanent outdoor installation, TheMATCHBOX is housed in a rugged, weatherproof aluminum enclosure that mounts directly at the antenna feed point. Integrated top and bottom mounting flanges allow for secure attachment to a wide variety of support structures, providing a durable and reliable solution for LF and MF antenna systems
Not Yet Reviewed
$595.00
DX Engineering Maxi-Core® High-Power Multi-Band UNUNs
DX Engineering High-Power Multi-Band UNUNs with Maxi-Core® technology allow your antenna to perform to its fullest potential and reduce stress on your equipment. These specially tuned UNUNs, designed for non-resonant vertical antenna applications, operate more efficiently than similar competitive products. Lesser products may burn up easily on lower bands with QRO power levels. DX Engineering high-power UNUNs are specifically designed for applications with 43 ft. non-resonant, multi-band antennas, ensuring the best efficiency from your antenna and transmission line/tuner installation. The results are minimizing the additional transmission line losses caused by abnormally-high SWR. DX Engineering Maxi-Core® High-Power Multi-Band UNUNs can be added to any existing 43 ft. antenna installation or used to replace an older competitive UNUN for a performance increase. The UN-43-R includes mounting bracket and feed-point connections braids. Note: Whenever the DX Engineering "Documentation" tab is available, please look at the associated files for additional product information. All non-resonant vertical antennas present high SWR to their feed lines. Deal with it! Order DX Engineering High-Power Multi-Band UNUNs!
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$201.99
Momobeam RFC-SC Single Core 1kW RF Choke Baluns
Momobeam RFC SC Single Core 1 kW RF Choke Baluns are efficient broadband common mode current (CMC) chokes designed to ensure proper current balance and clean transitions between balanced resonant antennas—such as dipoles and Yagi antennas—and unbalanced coaxial feed lines. By delivering excellent suppression of unwanted CMC across a wide frequency range, these RF chokes help maintain optimal antenna performance and protect sensitive station equipment. Common mode currents can cause a variety of station problems, including elevated receiver noise levels, inaccurate SWR measurements, and interference affecting nearby electronic devices or equipment within the shack. The RFC SC effectively prevents these issues by stopping CMC from traveling on the outside of the coaxial shield, ensuring cleaner transmit and receive performance under all operating conditions. Thanks to its broadband characteristics, the RFC SC can be used with virtually any 50 ohm feed antenna system. It is ideal for Yagi antennas, resonant dipoles, and any installation where clean feedline behavior is essential. The choke also serves as an excellent replacement for damaged or aging 1:1 RF chokes or baluns, offering improved suppression and modern build quality. With robust performance, wide compatibility, and reliable common mode current elimination, the Momobeam RFC SC Single Core 1 kW RF Chokes provide a simple yet essential upgrade for ensuring your antenna system operates at its best.
Not Yet Reviewed
$144.99
Momobeam RFC-DBC Dual Big Core 4kW RF Choke Baluns
Momobeam RFC-DBC Dual Big Core 4kW RF Choke Baluns are efficient broadband common mode current chokes designed to ensure proper current balance and clean transitions between balanced resonant antennas—such as dipoles and Yagi antennas—and unbalanced coaxial feed lines. By delivering excellent suppression of unwanted common mode current across a wide frequency range, these RF chokes help maintain optimal antenna performance and protect sensitive station equipment. Common mode currents can cause a variety of station problems, including elevated receiver noise levels, inaccurate SWR measurements, and interference affecting nearby electronic devices or equipment within the shack. The RFC DBC effectively prevents these issues by stopping common mode current from traveling on the outside of the coaxial shield, ensuring cleaner transmit and receive performance under all operating conditions. Thanks to its broadband characteristics, the RFC DBC can be used with virtually any 50 ohm feed antenna system. It is ideal for Yagi antennas, resonant dipoles, and any installation where clean feedline behavior is essential. The choke also serves as an excellent replacement for damaged or aging 1:1 RF chokes or baluns, offering improved suppression and modern build quality. With robust performance, wide compatibility, and reliable common mode current elimination, the Momobeam RFC-DBC Dual Big Core 4kW RF Choke Baluns provide a simple yet essential upgrade for ensuring your antenna system operates at its best.
Not Yet Reviewed
$229.99
Momobeam RFC-DC Dual Core 2kW RF Choke Baluns
Momobeam RFC-DC Dual Core 2kW RF Choke Baluns are efficient broadband common mode current chokes designed to ensure proper current balance and clean transitions between balanced resonant antennas—such as dipoles and Yagi antennas—and unbalanced coaxial feed lines. By delivering excellent suppression of unwanted common mode current across a wide frequency range, these RF chokes help maintain optimal antenna performance and protect sensitive station equipment. Common mode currents can cause a variety of station problems, including elevated receiver noise levels, inaccurate SWR measurements, and interference affecting nearby electronic devices or equipment within the shack. The RFC DC effectively prevents these issues by stopping common mode current from traveling on the outside of the coaxial shield, ensuring cleaner transmit and receive performance under all operating conditions. Thanks to its broadband characteristics, the RFC DC can be used with virtually any 50 ohm feed antenna system. It is ideal for Yagi antennas, resonant dipoles, and any installation where clean feedline behavior is essential. The choke also serves as an excellent replacement for damaged or aging 1:1 RF chokes or baluns, offering improved suppression and modern build quality. With robust performance, wide compatibility, and reliable common mode current elimination, the Momobeam RFC DC Dual Core 2kW RF Chokes provide a simple yet essential upgrade for ensuring your antenna system operates at its best.
Not Yet Reviewed
$180.99
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