After obtaining my B license last year, as a beginner in shortwave radio, I encountered many problems. One of the biggest challenges was choosing an appropriate antenna. By chance, I discovered a video by "Chengdu M" and his antenna products. After some intermittent exploration, I finally achieved some long-distance communication this year. This article will share my experience and suggestions for using Chengdu M's antennas. If you just want to see the conclusion, you can skip directly to the end.
Exploration process
MA-01 and the transport vehicle
Since I live in a high-rise building, but the distance to the roof is quite large, and my initial interest in mobile operation was not very strong, I initially planned to operate from my car. I also purchased an FT-891, which is suitable for use in vehicles.
Since I was planning to use it in my car, I found the MA-01 antenna, which is specifically designed for automotive use. At the time, I didn't understand much about antennas, but I thought that using a specially designed one would be effective, and since the price wasn't too high, I decided to buy it.
The installation methods for both the shortwave and UV band car consoles are similar. You can find specific installation procedures in video tutorials or by asking experienced users who have installed car consoles. The shortwave antenna can also be mounted on the rear of the car using a bracket or on the roof using an adhesive disc. Since I had already installed the UV radio in the car, installing the 891 didn't require much effort.
Unlike the U-shaped antenna, a shortwave antenna requires grounding to prevent excessive standing wave ratios. Through my own experiments, I found that using a single magnetic car mount was not always effective, but using two mounts worked well. The 7MHz frequency requires a higher level of grounding, and may require an additional one. It is important to note that the magnetic mounts are not ground wires; the vehicle itself provides the ground connection, while the magnetic mounts or copper mesh straps are used to connect the antenna to the vehicle.
After installation, occasionally drive to a location and perform connectivity tests. I found that the MA-01 antenna could not transmit SSB, but FT8 reception and transmission were still possible. Even in a parking lot within the city, under good conditions, it was possible to connect to one or two stations. However, don't expect great results, as it is a short gain antenna; if you can connect to something, that's already good enough.
Long-term grazing period
The MA-01 did not perform as expected; the shortwave radio and antenna were covered in dust inside the car. Because the shortwave antenna was designed to be easily installed and removed, it didn't show signs of age or wear.
MA-12 and 野架
After researching and browsing forums, I learned that to achieve good results with shortwave GP antennas, it is necessary to purchase a full-size antenna. In Mr. M's house, there was an MA-12 antenna.
The MA-12 is designed for use in the field, requiring a clear area and the insertion of ground rods into the soil. Since it doesn't have a battery, it needs to be powered by a car, so I started looking for a suitable location where I could park the car. Fortunately, it was springtime, which meant good shortwave propagation, and the first time I used it, the results were excellent.
After successfully connecting, I gained confidence in the MA-12 antenna. However, while there were many potential locations, it wasn't easy to find a place where I could park my car directly and easily access it. The location was also quite far from home. So, I started researching setting up the antenna directly. It turned out not to be that complicated; all I needed was a battery and a power cable. I bought a battery from M (I got it on Xianyu, but couldn't find one on Taobao), and made my own cable, so I could now set up the antenna conveniently near my home.
MA-01 and Fishing Rod Antenna
Although the MA-01 was discarded, many balcony fishing antennas were also MA-01 models, indicating that it could be useful at different times.
The main problem that fishing rod antennas need to solve is reducing the standing wave ratio (SWR). The only way to reduce SWR is by using a ground plane. I previously didn't fully understand the concept of a "ground plane," and mistakenly thought it was simply a "ground wire." In fact, I even tried creating a ground wire to test, but unfortunately, I couldn't lower the SWR.
Through intermittent experimentation, I discovered that the ground plane doesn't necessarily need to be a perfect ground wire. As long as the antenna extends outside the window and you connect two wires randomly, adjust the feedline and the position of the wires, the VSWR will immediately decrease. In a GP system, the ground plane and the antenna are in a vertical relationship: the antenna is mounted horizontally, and the ground plane is simply placed on the ground, resulting in a vertical configuration. This allows me to use the MA-01 fishing rod antenna as a communication antenna at home.
Because it's easy for mosquitoes to enter through the windows, and there are no fixed places to attach things near the windows, I measured the window size and bought a small hook that fits perfectly. The MA-01 is lightweight, so there's no need to worry about falling objects from above:
This method is suitable for 20 meters or higher frequencies, while 40 meters requires a very high ground net. It's difficult to achieve good results with this method, so it's best to consider using an elevated mast.
MA-56 base
This year, M-哥 launched a new product: the MA-56 base. Although this base is relatively expensive, it solves a problem by directly connecting the pull rod to the suction cup or feed line. With this base, you can use a 5.6-meter pole as long as you can park, and you don't need to find a dedicated space. The ground net can also be used directly with the vehicle body, making it even easier to set up. In the hot summer, you can sit in the car while enjoying air conditioning and staying connected.
Conclusion
I don't know how to use it.
New shortwave enthusiasts can start with the MA-12 antenna, along with accessories such as batteries, for use in a field setup.
The MA-12 antenna set is complete, except for the radio and related accessories. You only need to purchase a longer coaxial cable. The MA-12 has frequency markings; by following these markings, you can achieve natural resonance without needing to buy a separate nanoVNA or antenna tuner.
Car-related
For car use, I recommend purchasing a 5.6m pull rope, along with the MA-56 antenna base and magnetic sticker provided by M, for use in the vehicle. The following is the shopping list:
- M's MA-56 antenna base
- A 5.6-meter puller: It doesn't have to be from M's place; it just needs to be strong enough and have an M10 thread. The MA-12 puller scale is not applicable, so you need to mark it yourself.
- The 7 MHz coil of the MA-12: For use in the 40m band.
- Use 2-3 car-mounted shortwave magnetic patches, or use copper woven wire and ordinary electrical wire as a ground.
- nanoVNA: When adjusting the length of the tuning lever, use nanoVNA to observe the standing wave ratio.
It is recommended to only install the antenna when connected, and remove it when not connected. Ensure that the feed line or suction cup has a waterproof cover.
Brother M has a set of MA-01 antennas specifically designed for cars. Although these antennas are designed for car use, they are still gain antennas, and their efficiency and performance are not as good as full-size antennas. I don't recommend using them.
Balcony fishing rod antenna
Mount on the balcony. We do not recommend using the MA-01 antenna, as it has low efficiency and does not provide particularly good results. However, if you are concerned about falling objects from high places and are unwilling to use a 5-meter antenna, or if you already have an MA-01 and just want to experiment with FT8 or CW, you can consider using it. Here is a shopping list for the antenna feed system:
- MA-01 antenna
- Coils: 30m (10MHz), 17m (18MHz), 12m (24MHz), and 6m (50MHz). These frequency bands require separate purchase. Low-frequency bands like 60m (5MHz) and 40m (7MHz) require very high ground conditions, making them difficult to operate. Even with a powerful transceiver, it can be challenging to establish communication, so caution is advised when purchasing.
- nanoVNA: When adjusting the length of the tuning lever, use nanoVNA to observe the standing wave ratio.
- Grounding: You can purchase a grounding wire that can be easily torn apart, or simply use a few wires to create a grounding system.
- Clamps, or other devices that can securely hold the antenna in place.
Intended for fixed use
The M-brother antenna is not suitable for long-term, fixed use. If you want to use it as a base station antenna, consider other products such as the GP4 antenna: This antenna is designed for fixed installation and uses an attenuator to support multiple frequency bands simultaneously.
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