The MFJ-259D is a highly popular Antenna Analyzer with an expanded frequency range of 100 kHz-230 MHz and 2200-meter band. It provides an instant display of SWR, complex antenna impedance, and frequency, giving users a comprehensive understanding of their antenna. The analyzer offers simultaneous readings of SWR, return loss, and reflection coefficient at any frequency. It also measures complex impedance as series resistance and reactance or as magnitude and phase. Additionally, it can determine velocity factor, coax cable loss, length of coax, and distance to short or open in feet. It can also measure inductance and capacitance at actual operating frequencies.

This all-in-one ham radio test set includes a frequency counter, RF generator, SWR analyzer, RF resistance, reactance analyzer, coax analyzer, capacitance/inductance meter, and more. The large two-line LCD screen and side-by-side meters provide clear and easy-to-read information. With this analyzer, users can find their antenna's resonant frequency, trim dipoles and verticals for optimal SWR, adjust various types of antennas, and modify antenna spacing and height. The displays show real-time changes in SWR, resistance, and reactance, helping users make informed decisions.

The MFJ-259D allows for quick tuning of critical HF mobile antennas, ensuring excellent DX performance without risking high SWR. It also enables the measurement of an antenna's 2:1 SWR bandwidth and the analysis of multiband performance. Users can check SWR and ham bands without transmitting, avoiding FCC violations, and fine-tune their antenna tuner for a perfect 1:1 match. The analyzer simplifies the process of building and adjusting matching networks, baluns, and antennas. It accurately measures the distance too short or open in failed coax, coax length, loss, velocity factor, and impedance. Additionally, it helps troubleshoot resonant frequency, traps, stubs, transmission lines, RF chokes, tuned circuits, and baluns.

The MFJ-259D features a built-in Ni-MH/Ni-CD charger circuit, battery saver, low battery warning, and smooth reduction drive tuning. It can be powered by 10 AA or Ni-MH batteries or 110-240 VAC with the optional MFJ-1312D. The rugged, compact all-aluminum construction makes it handheld and portable, with dimensions of 4Wx6¾Hx2D inches.