This year, I've revisited amateur radio and am primarily focused on shortwave. My school is located on the outskirts of the city, and the electromagnetic environment is reasonably good (I achieved the first SSB contact on shortwave with a G90S at 20W, callsign BY1BY), and in collaboration with teacher BG6AEC, we set up a 20-meter end-fed antenna on the roof of the vocational training building. The results were quite good, and I won a silver award during the Chinese Amateur Radio Festival for using a pull-out dipole. However, the hot summer climate is clearly not suitable for outdoor antennas, and there are also issues such as the lack of air conditioning in the vocational training room, which made me start considering the feasibility of setting up an antenna in my dormitory:
- The apartment building has six floors, and I'm on the third floor. The height is a bit awkward, and whether I lean out or look across to the opposite building, it's quite noticeable, so I've decided against it.
- Forward/Reverse: Regarding disassembly and assembly, let's not talk about installation on the roof first. Since it's impossible to install on the roof due to lack of a terrace, we give up.
3. Huan antenna: Low power tolerance, small balcony space, difficult to place, giving up.
4. Balcony pull-out drawer: A three-legged frame and base will do, I already bought a set of V-shaped pull-out drawers before, which are easy to assemble and disassemble, so I decided to use this one!
Around May, I started researching balcony-mounted antennas. I consulted online methods used by other enthusiasts and extended the metal rods to the appropriate length, then connected them to the coaxial cable. The ground wire was connected to the shielding layer, which further increased the effective length of the antenna. When I connected the radio, I was surprised to find that it was already resonating at 20 meters. I tuned it to a frequency used in the local market and started calling CQ. However, everyone continued talking amongst themselves, and there was no response to my calls. Undeterred, I connected a 100W amplifier that I had built myself some time ago. To my surprise, I received a QRZ call, but when I responded, it was like shouting into the void.
However, I did receive some responses on FT8, but they were almost all from Japanese radio stations. The signal quality was acceptable, but it was clear that there was no voice communication, which significantly reduced the fun. A few years ago, under similar circumstances, I chose to quit. Subsequently, I started wondering if there was a way to improve the efficiency of my balcony fishing antenna.
The first thing I considered changing was the placement of the ground cover, as the balcony is narrow. Therefore, I used an L-shaped ground cover that wouldn't block the path while also being compact; I then attached the ground cover to the railing, securing it at one end (as shown in the diagram below, a simplified view of the balcony from above):
Then, I called again – and received a response from a station in sector 7! The signal strength was around 100W, and the other party provided me with signal reports indicating that the ground network was effective. After communicating with another station in sector 7, I learned that this type of fishing antenna is called "GP Horizontal Antenna," which gave me an idea for optimization.
GP antennas, traditionally installed on muddy surfaces, required stakes to ensure good contact with the ground. The vibrating element (the antenna itself) had a length of only 1/4 wavelength, which did not meet the requirements for a half-wave antenna. Therefore, good contact with the ground created an equivalent vibrating element to achieve an effective half-wavelength. However, when the surface was not muddy or relatively dry, the grounding network became important. Spreading out a grounding network effectively created an equivalent ground connection. Of course, enthusiasts may have heard that raising the grounding network can improve efficiency and reduce the number of grounding stakes. This is particularly suitable for GP antennas operating at higher frequencies.
Similarly, since the antenna is coming from above, the ground network also needs to be positioned accordingly; considering the actual environment of the balcony, simple adjustments resulted in this effect: (Balcony facing diagram)
I also optimized the connector part to create an upward angle at the base of the antenna, which helps to prevent the pull-rod from drooping.
(by) @BG6AEC Please help me design the base for cutting.
Since I set up the antenna, this balcony fishing rod has allowed me to complete dozens of single-sideband (SSB) communications and hundreds of FT8 communications, including my first SSB contact in the 0 zone, as well as digital mode communications with several European and American countries (all at 100W power, using equipment such as a G90S+100W amplifier, an ICOM IC-718, and a Yaesu FT-DX10). Overall, the results have been quite good.
Of course, this antenna also has several drawbacks, such as:
- The background noise was very loud, with interference from air conditioners, numerous outdoor units, and various noises coming from the dorms. The most significant noise source was always around S7-S9.
- The frequency band is limited, primarily in the 20-meter band. After testing, adjusting the antenna on the 6-meter band also achieves resonance. The standing wave ratio (SWR) in the 10-meter band is between 2 and 3, which is usable. However, the SWR in other bands is greater than 8. While the internal antenna adjustment of the G90S can somewhat reduce the SWR, it doesn't have practical use. It's also difficult to establish communication using FT8.
- Floor restrictions: I'm on the third floor, and there are two buildings opposite my balcony. Fortunately, the large hall between these two buildings is only two stories high, leaving a gap. The main usable directions are south and west. Currently, the most connected towers are in Guangdong, Guangxi, Sichuan, and Chongqing, while the signal to the north is weaker, mainly for basic digital communication.
Here are my experiences using the balcony fishing rod antenna pull-up antenna over the past few months. I would appreciate any corrections or suggestions from experienced users, and I will also continue to experiment with other forms of balcony antennas. I also welcome fellow enthusiasts to share their experiences with balcony antennas. This is BG6HFD, 73!
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