Easy To Power
MFJ-225 can be powered by four AAA alkaline batteries or four AAA Ni-MH rechargeable batteries (batteries not incl.). Optional MFJ-1312D, or any external 12 VDC power is required for the built in recharging circuit with charge indicator LED. LED will light while charging and turn off when cycle is completed. On the bench, power it through the USB power port using any USB power source. Optional USB cable,MFJ-5430

Self-Calibrating
In order to maintain out-of-the box accuracy, all analyzers require periodic calibration checks -- a potentially time-consuming operation that may require special RF loads and step-by-step procedures. However, the MFJ-225 uses built-in firmware to perform its entire calibration routine in less than a second! Simply initiate the "calibrate" command and you`re done!

Specifications
MFJ-225 requires 4 NiMh AAA cells or optional power adapter MFJ-1312D, $15.95.
PC interface requires a USB Type-B cable. Analyzer`s OUT port is SO-239. IN port
is SMA-female. 3 3/32W x 6 1/8H x 1 1/2D inches.