MFJ MFJ-854, Manual

Introduction 
 

Congratulations on purchasing the MFJ-854 RF-Current Meter.  The MFJ-854 is 
designed for measuring current distribution on antenna elements and radials, and for 
checking common-mode current levels on coaxial feedlines and grounds.  It also works 
well for tracking down RFI-causing current on household wiring and cables.  Here are 
some important features we think you'll like: 
 

Wide Range:  

Measures RF current from as little as 1 mA to 3 Amps in six ranges. 

Full HF Coverage:  

Accurate from 1 MHz to 30 MHz and beyond.

Low Interaction:  

Sense coil has minimal effect on circuits under test.

Large Cable Capacity:  

Accepts cables up to approximately 1/2" in diameter. 

Accurate:

  Diode-compensated Op-Amp delivers improved meter linearity. 

Rugged: 

 Built to last with a sturdy all-aluminum case and G-10 pc board.   

Battery Saver: 

Press-to-test power circuit turns unit off automatically after 15 seconds.

Long Battery Life:  

Meter draws 3-mA, battery's service life approaches shelf life.

Handheld Size:  

Weighs 11 ounces, only 2.3" x 1.6" x 6.5" (including sense coil). 

Controls and Locations 
 

Sensitivity

Power

On

<30mA

Adj

30mA

100mA 300mA

1A

3A

Ampres

2

3

4

5

MFJ-854

Cable

1

6

9-V

 
1. Sense Coil:

  Clamps onto conductor under test, accepts diameters to around 1/2" . 

2. Meter:  

Calibrated scale indicates readings in mA or Amps. 

3. Range:

  Selects from six measurement ranges. 

4. Sensitivity:  

Works on <30 mA range, adjusts gain for low-level measurements.

5. Power On:  

Momentary switch applies power, activates 15-second power-off delay. 

6. Battery Clip:  

Accepts any standard 9-V

flat-pack battery.