MFJ-842 Mobile VHF/UHF SWR/Wattmeter
Instruction Manual
2
MFJ-842 Mobile HF/VHF SWR/Wattmeter
Introduction
The MFJ-842 Mobile VHF/UHF SWR/Wattmeter measures forward and reflected power
and SWR simultaneously and is designed to operate on 140-525 MHz. The MFJ-842 has
two power scales, which are selected with a push button switch. The high power scale
measures 0-150 Watts forward power and 0- 50 Watts reflected power. The low power
scale measures 0-15 Watts forward power and 0-5 Watts reflected power. The MFJ-842
utilizes an illuminated Cross-Needle meter to read the SWR from 1:1 to
∞
. This compact
SWR/Wattmeter is rugged enough to take the abuse of brutal mobile and portable
operation.
Specifications
Frequency Range:
140-525 MHz
Input Impedance:
50
Ohms
Power Range:
15 and 150 Watts Forward Power
5 and 50 Watts Reflected Power
Power Accuracy:
10% at full scale
Minimum Input Power:
1
Watts
Connectors:
UHF (M type)
Dimensions:
3.35”W x 3.43”H x 3.74”D
Weight:
0.62
lb
Lamp Input Power:
12 VDC
Installation
1. Connect your transmitter to the connector labeled
TX.
on the back of the unit and
connect your antenna to the connector labeled
ANT.
on the back of the unit. It is
important that you use good quality coax and properly installed connectors.
2. An internal lamp backlights the meter scale. The lamp circuit requires 12 VDC
supply such as the MFJ-1312B. Use a 2.1 mm coaxial plug with the center
conductor positive and the sleeve ground.
3. To measure the power output capability of a transmitter/amplifier you should
connect a quality 50-ohm dummy load to the
ANT.
connector of the MFJ-842.