BALUN DESIGNS 1115U Isolation 5KW

( Brand: Balun Designs ), ( Manufacturer Part Number: 1115U ), ( Compatible Brand: Universal ), ( Type: Isolation Balun ), ( Band: Hf ), ( Features: Uhf Connectors ), ( To Fit: Ham Radio Transceiver ), ( Country Of Origin: United States )

Review BALUN DESIGNS Isolation 5kw Model

The **Balun 1115U Isolation 5kW** is a high-performance, ruggedly engineered current balun designed specifically for demanding RF applications where isolation, efficiency, and reliability are paramount. This robust unit is built to handle substantial power levels up to **5 kilowatts continuous duty**, making it an ideal choice for professional radio amateurs, emergency communication systems, and industrial RF applications where signal integrity and safety are critical. The **1115U model** features a **high-voltage isolation rating**, ensuring protection against ground loops, static discharge, and potential electrical hazards that could compromise both equipment and operator safety. Its compact yet durable construction incorporates **high-quality materials**, including reinforced insulation and a sturdy metal housing, to withstand harsh environmental conditions, including exposure to moisture, dust, and temperature fluctuations.

At the core of this balun s functionality is its **1:1 current transformation ratio**, which ensures minimal signal loss while maintaining optimal impedance matching between transmission lines and antennas. The **isolation feature** prevents unwanted RF feedback, ground loops, and interference, which is particularly valuable in multi-antenna setups or when operating in electrically noisy environments. The **5kW power handling capability** is achieved through advanced thermal management, allowing for extended operation without overheating, even under peak load conditions. This makes the 1115U a dependable solution for high-power applications such as **HF/VHF/UHF transmitting systems, amateur radio repeaters, and industrial RF heating or welding equipment**.

The design emphasizes **versatility**, with a **threaded mounting system** that allows for secure installation in various setups, including coax cable connections, antenna towers, or equipment racks. Its **low insertion loss** ensures that signal integrity remains intact across a wide frequency range, from **1.8 MHz to 30 MHz**, making it suitable for a broad spectrum of communication frequencies. Additionally, the balun s **high common-mode rejection ratio** minimizes unwanted radiation and interference, further enhancing performance in critical applications. Whether used in **emergency communications, military-grade RF systems, or high-power amateur radio operations**, the **Balun 1115U Isolation 5kW** delivers uncompromising reliability, efficiency, and protection making it a cornerstone component for serious RF professionals who demand nothing less than excellence.

The **Balun 1115U Isolation (5kW)** is a common choice for amateur radio operators, especially those working with HF antennas and transmitters. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the Balun 1115U Isolation (5kW)**

1. **High Power Handling (5kW)**

The unit is rated for 5kW of continuous power, making it suitable for high-power HF transmissions. This is ideal for operators running 1.5kW 2kW transmitters or those planning future upgrades.

2. **Isolation Design**

The "Isolation" variant includes a built-in isolation transformer, which helps prevent RF feedback into the feedline. This is particularly useful when operating with high-power amplifiers or when dealing with noisy environments, as it reduces the risk of arcing or damage to the transmitter.

3. **Wide Frequency Range (1.8 30 MHz)**

The balun covers the entire HF band (160m 10m), making it versatile for general-purpose use without the need for multiple units.

4. **Durable Construction**

The 1115 series is known for robust construction, often featuring high-quality materials like copper conductors and insulated terminals. This ensures reliability in both indoor and outdoor installations.

5. **Commonly Available and Affordable**

As a well-established product, the 1115U is widely stocked by amateur radio suppliers, and its price is reasonable compared to custom or high-end alternatives.

6. **Easy Installation**

The unit is compact and designed for straightforward mounting, whether in a shack, tower, or antenna tuner setup. It typically comes with BNC or SO-239 connectors, which are standard in HF rigs.

7. **Reduces Common-Mode Currents**

Like all baluns, it helps suppress unwanted RF currents on the outer shield of coax cables, improving efficiency and reducing interference.

8. **Compatibility with Antenna Tuners**

Many operators use this balun in conjunction with antenna tuners (e.g., MFJ-989, ATU-1000), and its 5kW rating ensures it won t be a bottleneck in the system.

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### **Cons of the Balun 1115U Isolation (5kW)**

1. **Limited Bandwidth for Some Applications**

While it covers 1.8 30 MHz, its performance at the extremes (e.g., 1.8 MHz or 28 30 MHz) may not be as optimal as specialized baluns designed for those bands. For narrow-band applications (e.g., 6m or 10m only), a dedicated balun might offer better efficiency.

2. **No Built-in SWR Protection**

The 1115U does not include an automatic SWR protection feature. If the antenna is severely mismatched (high SWR), the transmitter may still be at risk of damage unless protected by an external SWR meter or tuner.

3. **Physical Size and Mounting**

While not overly large, the unit requires space, especially if installed outdoors. Its weight and bulk may be a consideration for compact setups or mobile operations.

4. **Potential for Overheating at Peak Power**

Although rated for 5kW, prolonged operation at maximum power (especially in high-temperature environments) could lead to thermal stress. Proper ventilation is recommended.

5. **Connector Quality Varies by Manufacturer**

Some aftermarket or budget versions may use lower-quality connectors, which could degrade over time. High-end versions (e.g., from MFJ or other reputable brands) tend to have more reliable terminals.

6. **Not a Replacement for a Good Antenna Tuner**

While the balun improves feedline performance, it does not compensate for poor antenna design or tuning. Operators still need a proper antenna tuner or matching network for optimal performance.

7. **Limited Use Above 30 MHz**

The unit is not suitable for VHF/UHF (e.g., 2m, 70cm), so users requiring multi-band operation will need additional baluns for those frequencies.

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### **Conclusion**

The **Balun 1115U Isolation (5kW)** is a solid, high-power balun for HF amateur radio operators who need a reliable, versatile solution for their feedlines. Its 5kW rating, wide frequency coverage, and isolation features make it a practical choice for most home stations. However, it is not a universal fix it requires proper installation, complementary equipment (like an antenna tuner), and awareness of its limitations (e.g., bandwidth, connector quality).

For operators running high power, this balun is a cost-effective way to protect their feedlines and transmitters. Those needing ultra-wideband performance or specialized applications (e.g., vertical polarization, narrow-band use) may still benefit from supplementing it with additional baluns or tuners.

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### **Recommendation**

- You operate in the HF bands (1.8 30 MHz) and need a reliable, high-power balun.

- You want to reduce common-mode currents and improve feedline efficiency.

- You re on a budget but still need a durable, widely available solution.

- You plan to use it with an antenna tuner for matching purposes.

- You need performance at the very low (1.8 MHz) or high (28 30 MHz) ends of the spectrum pair it with a dedicated balun for those bands.

- You lack an antenna tuner this balun alone won t compensate for poor antenna matching.

- You operate above 30 MHz you ll need separate baluns for VHF/UHF.

- You re concerned about connector quality opt for a reputable brand (e.g., MFJ, Alpha Delta, or homebrew options with high-quality terminals).

**Final Verdict:** The Balun 1115U Isolation (5kW) is a **highly recommended** purchase for most HF operators due to its balance of power handling, versatility, and affordability. Pair it with a good antenna tuner and proper installation practices to maximize its benefits.

Details:

For Sale Balun Designs 1:1 Isolation 5kw model 1115U Good working unit, have a bunch of these and don't need as many.

part #: 1115u prices

• $59.00-$90.00

specifications hamamateuradio:

• brand: Balun Designs
• mpn: 1115u
• compatible brand: Universal
• type: Isolation Balun
• band: Hf
• features: Uhf Connectors
• to fit: Ham Radio Transceiver
• country of origin: United States

returns hamamateuradio:

• policy: No Returns

general hamamateuradio:

• Radio Communication > Ham, Amateur Radio > Other Ham Radio Equipment
• condition: Used

offer hamamateuradio:

• quantity: 1
• options: Ship-to-home
• sold: 0
• availability: In Stock
• best offers: True
• started: April 29, 2026

shipping hamamateuradio:

• transit: 5-10 Days
• type: Calculated
• carrier: USPS
• cost: $9.14
• class: Standard
• service: USPS Ground Advantage

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• other
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• credit card: Diners-club

seller hamamateuradio:

• rating: 100.0%
• # reviews: 436
• city: Cuyahoga Falls, Ohio

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