MFJ MFJ-870 User Manual
MFJ Enterprises, Inc.
300 Industrial Park Rd
Starkville, MS 39759 USA
MFJ-870 SWR & Power Meter Instruction Manual
This SWR & Power meter is a highly accurate RF meter for measuring Forward Power,
Reflected Power, and VSWR.
Main Features:
• Large meter display for easy reading.
• Forward RF power readings, switchable to indicate either average power of Peak
Envelop Power (PEP) for SSB and AM transmitters.
• Reflected RF power readings.
• VSWR ratios.
• Illuminated meter.
• Convenient control for easy operation.
Model MFJ-870
Frequency Range 1.6 - 60 MHz
Power Range 1W to 3KW
Power Scale 30W, 300W, 3KW
Maximum Power 3KW (up to 1 minunte maximum)
Accuracy +/- 10% (AVG)
VSWR Min Power required = 3 Watt for F.S.D.
Input/Output Impedance 50 Ohms
Input/Output Connectors SO-239
Dimensions (W/H/D) in 7.5 X 4.25 X 3
Weight (lbs) 1 lb 11oz
Accessories Instruction Manual & Lead wire with DC Plug
Front Panel
Back Panel
Explanation of Features:
1. Meter Display: Indicates Forward/Reflected Power in Watts and SWR ratio.
2. Function Switch: Selects Forward Power, Reflected Power , SWR SET, and SWR.
3. Range Switch: Selects RF Power Ranges of 30W, 300W, and 3KW.
4. SWR SET Control Knob: Sets full scale deflection when measuring SWR.
5. AVG/PEP Monitor: Selects Average or PEP RF Power Readings.
6. Meter Zero adjust: Mechanical zero adjustment for meter needle.
7. TX Connector: Coax connector to transmitter 50 Ohm RF output.
8. ANT Connector: Coax connector to 50 Ohm antenna system.
9. 13.8V DC connection for meter illumination.
Note: If meter lighting is required, use the DC cable enclosed and connect it to a 13.8V DC
source.
FORWARD POWER MEASUREMENT
1. Set the FUNCTION switch to the ‘FWD’ position.
2. Set the radio transceiver to transmit and read the scale corresponding to the Power
range selected (30W, 300W, or 3KW)
3. When the AVG/PEP button is ‘out’ the meter reads average RF power. When the
AVG/PEP button is depressed the meter reads Peak Envelope Power for use with SSB
and AM transmissions. In this mode there will be a slow rise and decay time.
REFLECTED POWER MEASUREMENT
1. Set the FUNCTION switch to the ‘REF’ position.
2. Set the radio transceiver to transmit and read the scale corresponding to the Power
range selected (30W, 300W, or 3KW)
3. When the AVG/PEP button is ‘out’ the meter reads average RF power. When the
AVG/PEP button is depressed the meter reads Peak Envelope Power for use with SSB
and AM transmissions. In this mode there will be a slow rise and decay time.
Loading...