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Exploring the Yaesu ATAS-25: A Versatile Portable Antenna for Ham Radio
The Yaesu ATAS-25 is a fascinating portable antenna that has gained attention among ham radio enthusiasts for its versatility and ease of use. This blog post delves into the features, performance, and practical applications of the ATAS-25, based on real-world experiences and testing. Whether you're a seasoned operator or new to the field, this guide will provide insights into making the most of this antenna.
Overview of the ATAS-25
The ATAS-25 is a manually tuned antenna that covers a wide range of frequencies from 40 meters to 70 centimeters. Its design allows for variable frequency adjustments, making it adaptable for various operating conditions. The antenna is particularly useful for portable operations, whether you're setting up in a park, on a balcony, or in the field.
Understanding the Screwdriver Antenna Design
One of the key features of the ATAS-25 is its "screwdriver" design. This type of antenna adjusts its inductance by rotating a coil, which can either increase or decrease the inductance based on the position of the antenna. The ability to quickly fine-tune the antenna is a significant advantage, especially in portable settings where conditions can change rapidly.
Power Handling and Efficiency
The ATAS-25 can handle up to 100 watts of power, making it suitable for use with a range of transceivers. While it may not be as efficient as full-sized antennas, the performance loss is relatively minor—approximately 4 dB, which translates to about one S-point in signal strength. For many operators, this trade-off is acceptable given the antenna's portability and ease of setup.
Components and Setup
The ATAS-25 consists of several key components:
- Base Unit: Contains the variable coil for tuning.
- Whip Antenna: Comprised of three screw-together sections.
- Radials: Includes radials for both 2 meters and 70 centimeters, enhancing performance on those bands.
The base of the antenna features a standard thread, allowing it to be mounted on a camera tripod. This flexibility is advantageous, as camera tripods are widely available and often more sturdy than other mounting options. The ability to adjust the antenna height can significantly improve performance, especially in areas with obstacles.
Preparing for Use
When preparing to use the ATAS-25, it's essential to establish a good ground system. This can involve laying out radials on the ground or using elevated radials, which generally perform better. During testing, elevated radials were used to enhance the antenna's performance, and the results were promising.
Real-World Testing Experience
During a recent trip to Suffolk, the ATAS-25 was put through its paces. The testing location was ideal—situated in a quiet area with minimal interference, making it perfect for evaluating the antenna's capabilities.
Setting Up the Antenna
The antenna was mounted on a sturdy camera tripod, with elevated radials for optimal performance. The setup was straightforward, and the adjustable nature of the antenna made it easy to fine-tune for the 20-meter band, which was open during testing.
Performance Observations
Contacts were made successfully on SSB, and the VSWR readings were impressive. The antenna showed good performance on 20 meters, with operators reporting clear signals. Although attempts to test the 2-meter band were less successful due to a lack of activity, the setup was still effective for monitoring air traffic, demonstrating the versatility of the antenna.
Future Applications
A particularly interesting aspect of the ATAS-25 is its potential for vehicle mounting. Although the antenna is primarily designed for portable use with tripods, there are possibilities for static use on a vehicle roof. Further experimentation is planned to explore this avenue, promising exciting results for future operations.
Considerations for Use
While the ATAS-25 is an excellent choice for portable operations, a few considerations can enhance user experience:
- Choose the Right Tripod: A sturdy tripod can make a significant difference in stability and overall performance.
- Use Elevated Radials: This setup generally yields better results compared to ground-mounted radials.
- Fine-Tune Regularly: Adjusting the coil frequently can help maintain optimal performance, especially in changing conditions.
Conclusion
The Yaesu ATAS-25 is a remarkable portable antenna that offers flexibility and performance for ham radio operators. Its screwdriver design allows for quick adjustments, making it ideal for portable setups where conditions may vary. With the capability to handle 100 watts and cover a broad frequency range, the ATAS-25 stands out as a practical choice for both new and experienced operators.
As operators continue to explore its potential, the ATAS-25 is sure to become a staple for those looking to operate in diverse locations. Whether you’re a casual user or a dedicated enthusiast, this antenna can enhance your portable ham radio experience.
For those interested in purchasing the ATAS-25, it is readily available with quick delivery options. Embrace the adventure of portable ham radio with the ATAS-25!