MFJ-860 SWR/Wattmeter Instruction Manual
1
MFJ-860 HF SWR/Wattmeter
The MFJ-860 HF SWR/Wattmeter measures forward and reflected power and indicates
SWR for the ham bands from 160 meters to 6 meters. The MFJ-860 has 2 power scales
which are selected with the front panel push button switch. The low power scale reads
from 0-30 watts forward and 0-6 watts reflected. The high power scale reads from 0-300
watts forward and 0-60 watts reflected. SWR is indicated from 1:1 to
∞
.
Connections
Connect your transmitter to the connector labeled "TRANSMITTER" and your antenna to
the connector labeled "ANTENNA". It is important that you use good quality coax and
properly installed connectors.
If you want to measure the power output capability of a transmitter/amplifier you should
connect a quality dummy load (50 ohms) to the antenna jack of the MFJ-860.
Caution: many HF dummy loads exhibit SWR especially on 15 and 10 meters.
The MFJ-860 has an illuminated meter. To
provide power for the meter lamp, a 12 Vdc
supply such as the MFJ-1312B should be used.
Use a standard 2.1 mm coaxial plug with the
center conductor positive and the sleeve ground.
Using the MFJ-860
To measure forward and reflected power press the selector switch to the correct power
setting. Transmit a steady carrier and read the power from the meter. Each unmarked
picket on the scale is an even division between the adjacent marked values. SWR is read
from the SWR curve closest to where the meter needles cross.
If a more exact reading of SWR is needed you may
use the equation for SWR. Measure the forward
and reflected power then put the values into the
following equation.
SWR = 1 +
Pr
Pf
1-
Pr
Pf
Pr = Reflected Power
Pf = Forward Power
F
H
G
I
K
J
F
H
G
I
K
J
