Marius Lubbe ZS1ML

As a ham radio operator, discovering an adaptable and cost-effective antenna can significantly enhance your experience. The MFJ-1778 G5RV antenna, named after its inventor Louis Varney (G5RV), is a multi-band wire antenna designed to cover all amateur bands from 80 to 10 meters. Its simplicity, affordability, and effectiveness across a broad range of frequencies have made it a favourite among the ham radio community.

The MFJ-1778 G5RV antenna is a full-size antenna measuring 31.09 meters (102 feet) in length, which is shorter than an 80-meter dipole. It can be configured as an inverted vee or sloper to fit into more compact spaces or even used as a Marconi antenna on 160 meters with a tuner and ground (But that is a technical issue for another article) Suffice it to say, that this antenna operates as is on 10m to 80m. The antenna can manage the full legal limit power, and to get it operational, all you need is to add a coax feedline. The MFJ-1778 is priced at $89.95 and can be purchased from the MFJ Enterprises website. While you are there also order the MFJ-915 RFI isolator at $49.95. One of the excellent range of MFJ-Tuners is also highly recommended with this antenna.


The MFJ-915 RF Isolator is a highly effective tool for ham radio operators. Its primary function is to reduce or eliminate Radio Frequency Interference (RFI), a frequent problem in radio communications that can degrade the performance of your radio equipment and even cause damage to other electronic devices in your vicinity.

RFI is unwanted radio frequency signals that interfere with your intended communication. This can be caused by a variety of factors, including other electronic devices, power lines, or even atmospheric conditions. The MFJ-915 RF Isolator works by isolating your antenna system from your radio, thereby reducing the stray RF that can cause these issues.

The device is designed to be placed in line with your antenna coax connection. It can manage up to 1.5 kW (1500 watts) of power, making it suitable for a wide range of applications. It operates within a frequency range of 1.8 MHz to 30 MHz, which covers most of the HF (High Frequency) band commonly used by ham radio operators.

The MFJ-915 RF Isolator is built with a mix of 31 ferrite core that provides maximum bandwidth and RF suppression. It’s housed in a heavy-duty PVC enclosure with SO-239 connectors, ensuring durability and reliable connections.

It’s important to note that when using a ladder line, you should try to keep it away from metal objects and at a distance from the ground, walls, and other obstructions. This is because ladder line is susceptible to changes in its surroundings, which can affect its impedance and, consequently, the SWR (Standing Wave Ratio).

In conclusion, the MFJ-915 RF Isolator is a valuable tool for any ham radio operator, helping to improve the performance of your radio equipment by reducing stray RF and preventing potential damage to your other electronic devices. And with the help of a balun, you can even connect a ladder line to an SO-239 connector, giving you greater flexibility in your setup.

When it comes to deployment, the MFJ-1778 G5RV antenna can be set up in various configurations depending on the space available and the operator’s specific requirements. The most common configurations are as a flat top or as an inverted V. In a flat top configuration, the antenna is strung horizontally between two supports, such as trees or masts. This configuration requires a large open space but often provides the best performance. In an inverted V configuration, the center of the antenna is raised, and the ends are angled downwards. This configuration requires less horizontal space and is often used when space is limited.

The MFJ-1778 G5RV antenna is a type of doublet antenna, which is essentially a dipole antenna fed with a specific length of ladder line or twin-lead, which acts as a matching section. The antenna consists of two wire elements, each approximately 15.54 meters (51 feet) long, connected to a length of ladder line or twin-lead, which is approximately 10.36 meters (34 feet) long. This ladder line acts as a matching section, allowing the antenna to operate on multiple bands.

The ladder line is connected to a balun, which is then connected to a length of coaxial cable. The balun helps to match the impedance of the ladder line to the impedance of the coaxial cable, allowing the antenna to be fed with a standard 50-ohm coaxial cable. It is recommended to use the MFJ-915 RFI isolator as a balun when connecting the ladder line to your coax. This isolator is designed to reduce radio frequency interference, which can improve the overall performance of your antenna system.

The antenna is typically supported at the center and the ends using insulators. The center of the antenna is usually raised to a height of 6.1 to 12.2 meters (20 to 40 feet) above the ground using a mast, tower, or tree. The ends of the antenna are also raised off the ground and can be tied off to trees, masts, or other suitable supports. The coaxial cable is typically terminated with an SO-239 connector, which allows the antenna to be easily connected to a ham radio transceiver.

While the MFJ-1778 G5RV antenna is designed to operate on multiple bands, it is not a resonant antenna on all bands. This means that an antenna tuner is often required to achieve a low SWR (standing wave ratio) on some bands. However, this type of antenna is well suited to using a tuner as it can tune up from 80m to 10m, which is a very versatile range.

The performance of the MFJ-1778 G5RV antenna varies depending on the band and the specific installation. However, user reviews suggest that the antenna generally performs well across a wide range of frequencies. Users have reported successful contacts all over the world using this antenna, often with reduced power. The antenna is reported to tune well on 80-20m and even up to 10m with a good tuner.

Some users have reported higher SWR on some bands and have had to use a tuner to achieve good results. Regardless of these reports, the MFJ-1778 G5RV antenna remains a popular choice among ham radio operators due to its versatility, affordability, and overall performance.

In conclusion, the MFJ-1778 G5RV antenna is a versatile and affordable option for ham radio operators looking to operate across a wide range of frequencies. Whether you’re a new operator looking to get on the air quickly or a seasoned ham looking for a reliable multi-band antenna, the MFJ-1778 G5RV is worth considering. As with any antenna, the key to getting the best performance out of the MFJ-1778 G5RV is proper installation and tuning. This antenna is a testament to the ingenuity and innovation in the world of ham radio, providing a practical solution for operators worldwide.

For detailed descriptions and instructions see the MFJ-1178 manual.


The G5RV antenna is a popular multi-band antenna used by amateur radio operators around the world. Its design is attributed to Louis Varney (G5RV), who was an English radio amateur and an engineer. Let’s delve into the history and design of this antenna.

The Early Years

Louis Varney was born in 1911 and became interested in radio at a young age. He was first licensed as a radio amateur in 1931. Varney was an engineer by profession and worked in the field of radio and telecommunications. His interest in radio and his engineering background led him to experiment with various antenna designs.

The Birth of the G5RV Antenna

The G5RV antenna was born out of Varney’s experiments in the late 1940s and early 1950s. He was trying to design an antenna that could operate efficiently on multiple bands, which was a challenge given the technology of the time.

The G5RV is essentially a dipole antenna, which is one of the simplest and most widely used antenna designs. A dipole antenna consists of two metal rods or wires of equal length, arranged end to end with a small gap in between. The G5RV, however, includes a specific length of ladder line or twin lead, which acts as a matching section to connect the dipole to the radio.

The Design

The original G5RV design is 31 meters (102 feet) long and is fed with a 10.36 meter (34 feet) section of 450-ohm ladder line. This ladder line is then connected to the radio using a coaxial cable. The antenna is designed to be resonant on the 20-meter band, but with the use of an antenna tuner, it can operate on multiple bands from 80 to 10 meters.

The G5RV antenna is typically installed as a flat-top, but it can also be installed as an inverted V if space is limited. The center of the antenna should be installed as high as possible, ideally at least 12 meters (40 feet) above the ground.

Legacy and Variations

The G5RV antenna has been widely adopted by amateur radio operators around the world due to its simplicity, affordability, and multi-band capabilities. Over the years, several variations of the G5RV have been developed to suit different needs and operating conditions. These include the G5RV Junior, which is a smaller version of the original design, and the ZS6BKW, which is an optimized version of the G5RV.

Louis Varney’s Legacy

Louis Varney passed away in 2000, but his contribution to amateur radio lives on. The G5RV antenna remains a popular choice for many radio amateurs, and Varney’s work continues to inspire new generations of radio enthusiasts.

In conclusion, the G5RV antenna is a testament to the ingenuity and passion of its creator, Louis Varney. It’s a simple, effective, and versatile design that has stood the test of time and continues to serve radio amateurs around the world.

73, Marius Lubbe ZS1ML

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