The MFJ-1664 antenna kit includes two telescopic radiators. The first is 1.5 meters long (60 cm when folded) and is made of flexible and durable stainless steel. It is for working from a moving vehicle or in confined spaces. The second telescopic radiator has a length of 3 meters (50 cm when folded). Due to the higher antenna efficiency, when using the second radiation, it is significantly increased.
An extension coil is provided at the base of the MFJ-1664 antenna. To achieve the highest quality factor, it is wound with a pitch with a silver-plated wire on a large-diameter plastic frame. Tuning the antenna into resonance is carried out using a metal “glass” moving along the extension coil and short-circuiting unused turns. The “glass” is connected to the antenna feed point where the antenna impedance is minimal. This inclusion simplifies the process of tuning to the operating frequency and allows the antenna to do without trial and error.
The entire lower part of the MFJ-1664 antenna is a single unit and is rigidly connected to the screw for mounting. Only a short-circuiting metal “glass” moves, the position of which, after adjustment, is securely fixed with a thumbscrew. Any 3/8″ threaded mount can be used to mount the antenna on the car. The maximum power supplied to the antenna is 200 Watts.