YAESU ATAS-25

The ATAS-25 is a manually-adjusted portable antenna ideal for field use with the HF Transceivers. Designed for mounting on a standard camera tripod (1/4" stud), the ATAS -25 is tuned by sliding the shorting ring of the loading coil up or down and selecting the appropriate number of top selections. Counterpoise wires are supplied
The ATAS-25 is contructed of high-grade materials for maximum efficiency, and it's the perfect traveling companion for your HF Transceivers!

Procedures for antenna adjustment
1. Referring to the following picture, raise and lower the coil assembly while listening to the band noise, and seek the position of the coil assembly producing the most noise in the receiver. If a peak in the sensitivity is not obtained when the coil assembly is fully retracted to the lowest (shortest) position, remove one radiating element from the coil assembly and try again. You may have a total antenna length that is too long.
2. Key the transmitter in the CW mode, and check the SWR meter reading.
3. Referring to the following picture again, carefully turn the coil assembly to the right or to the left while the transceiver is receiving. After making an adjustment, stand away from the antenna and check the SWR again, and repeat (or reverse) the procedure until the best SWR is obtained. Do not touch the coil assembly during a transmitting session.

Specifications

Frequency Range: 7/14/21/28/S0/144/430 MHz Amateur Bands
Height (Approx.): Max. 7.2 ft (2.2 m) during Operation / Min. 1.96 ft (0.6 m) for Transporting
Weight (Approx.): 2.05 lb (930 g)
Input Impedance: 50
Max Input Power: HF/SOMHz: 100W (SSB/CW,50% Duty) - 50W(AM/FM) - 144/430 MHz : 50W (ALL MODE)
Matched SWR : Less than 2.0 : 1