TRANSMITTER OPERATION

ACTIVE-TUNING ANTENNA SYSTEM (ATAS-100/-120)OPERATION

ATAS-100/-120 Operating Tips

The information below will help you derive the best performance possible from the ATAS- 100/-120Active-Tuning Antenna System.

Grounding

It is critically important that you establish a good mechanical and RF ground connection for your ATAS-100/-120(as with all vertical antennas). Mobile mounts which are bolted through the vehicle’s roof, or otherwise mechanically affixed, will usually be satisfactory. However, magnetic mounts do not provide the RF grounding necessary for good performance, and are not recommended for use with this antenna.

Tuning Procedure

The feedpoint impedance of the ATAS-100/-120(resistance and reactance) will necessarily vary over a wide range when you change bands. Occasionally, the transceiver’s micropro- cessor will not initially be able to determine the proper direction for the ATAS-100/-120to travel (inward or outward) for best SWR.

To resolve this situation, the transceiver will then command the ATAS-100/-120to retract fully to its minimum or maxmum height, and thence restart the tuning process. In this in- stance, the “WAIT” icon will remain on the display after you press the [A](TUNE) key. If this happens, do not press the [A](TUNE) key repeatedly. The transceiver will remain in the receive mode as it retracts (this may take up to one minute). Thereafter, the transmitter will be engaged, and the ATAS-100/-120will be automatically adjusted for best SWR. The “TUNE” icon will then disappear from the LCD, and you will be ready for operation.

External Wattmeters

If you wish to use an external wattmeter in conjunction with the transceiver and your ATAS- 100/-120, please check the wattmeter with an Ohmmeter prior to installation. Be sure there is a direct connection between the “In” and “Out” jacks of the wattmeter (zero resistance), and also ensure that there is a completely open circuit between the center pin and shield of the wattmeter’s output jack. Some wattmeters use a coil or other device which shorts the center pin to ground at DC, and this type of internal wattmeter circuitry will not allow the tuning function of the ATAS-100/-120to operate.

Operation on 30/17/12 Meters

Although the ATAS-100/-120is not specified for operation on the above bands, and opti- mum operation is therefore not guaranteed, the ATAS-100/-120generally can be tuned successfully on these bands (some manual adjustment may be required). Operation of the ATAS-100/-120on these bands will not damage the antenna’s components; please feel free to experiment on these bands, if you like.

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FT-857 Operating Manual

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Vertex Standard FT-857 manual ATAS-100/-120 Operating Tips, Grounding, Tuning Procedure, External Wattmeters
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FT-857 specifications

The Vertex Standard FT-857 is a compact and versatile all-mode transceiver that has become popular among amateur radio operators since its introduction. With its ability to operate in VHF, UHF, and HF bands, the FT-857 caters to a diverse range of communication preferences and provides exceptional performance for both mobile and base station applications.

One of the key features of the FT-857 is its coverage of a broad frequency range, spanning from 160 meters to 2 meters and covering the 70 cm band. This wide frequency coverage allows amateur operators to communicate with fellow enthusiasts across various bands, ensuring versatility in operational environments. The FT-857 offers an output power of up to 100 watts on HF and 50 watts on VHF/UHF, providing sufficient power for effective communication, whether in local or distant contacts.

Another distinctive characteristic of the FT-857 is its all-mode capability. It supports various modes of operation, including SSB, CW, AM, and FM, making it suitable for different operating styles and preferences. The inclusion of advanced digital signal processing (DSP) technology enhances audio clarity and offers noise reduction features, which are crucial in crowded bands. This DSP capability also aids in improving signal quality and overall communication experience.

Portability is a significant advantage of the FT-857. Its compact size and lightweight design make it an excellent choice for field operations and portable setups. Additionally, the transceiver is well-equipped with features such as built-in memory channels, allowing users to save and quickly access frequently used frequencies. The FT-857 also includes a built-in automatic antenna tuner, which makes it easier for operators to set up and optimize their antenna configurations without requiring additional external devices.

The FT-857 is designed with user-friendly controls and a clear LCD display, enabling operators to quickly adjust settings and monitor communication details without confusion. The visibility of the display is especially vital for use in different lighting conditions, ensuring that users can operate efficiently whether in bright sunlight or low light conditions.

In summary, the Vertex Standard FT-857 is a highly capable, compact transceiver that offers an effective solution for amateur radio communication. With its all-band, all-mode capabilities, robust DSP technology, and user-friendly design, the FT-857 remains a popular choice for both enthusiasts and professionals alike, facilitating engaging communication experiences across multiple bands and modes.
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