QRP Tuner, Wattmeter, & Dummy Load
MFJ-9219
INSTRUCTION MANUAL
©
2020
MFJ Enterprises, Inc.
300 Industrial Park Rd. Starkville, MS 39759
P: (662) 323-5869F: (662) 323-6551
Page 1: ...QRP Tuner Wattmeter Dummy Load MFJ 9219 INSTRUCTION MANUAL 2020 MFJ Enterprises Inc 300 Industrial Park Rd Starkville MS 39759 P 662 323 5869 F 662 323 6551...
Page 2: ...l handbooks or other official publications The copy of this manual provided to the customer will not be updated to reflect current data Customers using this manual should report errors or omissions re...
Page 3: ...IONS 5 3 SYSTEM SETUP 6 4 SYSTEM OPERATION 6 4 1 THERMAL WARNING 7 5 TECHNICAL ASSISTANCE 8 List of Figures 1 Horizontally polarized Electromagnetic Plane Wave 1 2 The Electromagnetic Spectrum 2 3 The...
Page 4: ...erted into signal by the radio The term electromagnetic field refers to the electric and magnetic environment existing at some location due to a radiating source such as an antenna Figure 1 Horizontal...
Page 5: ...d radiation visible light ultraviolet radiation and the entirety of the FCC spectrum allocation chart The RF part of the electromagnetic spectrum is generally defined as that part of the spectrum from...
Page 6: ...etermine an unknown resistance in a DC circuit but also works to determine unknown impedances in RF circuits Several variants exist but the one used in the MFJ 9218 can be simplified to the circuit sh...
Page 7: ...R2 Rx Rx R3 1 Finally if we extend our source to include AC or RF potentials and replace Rx with a load such as an antenna we can write Equation 1 in terms of reactances to get VBD V0 Z2 Z1 Z2 Zx Zx...
Page 8: ...enna match The compact and efficient T network will match just about any load and has a bypass in the event it is not needed Finally the resistive wattmeter is coupled to a 20W dummy load that is enga...
Page 9: ...s ready to operate Figure 6 MFJ 9219 Basic Setup 4 SYSTEM OPERATION Operating the MFJ 9219 is accomplished in two broadly defined stages First set the SWR Wattmeter for your radio and antenna Second e...
Page 10: ...position Adjust the TRANSMITTER and ANTENNA controls for the lowest SWR Continue this process until the lowest SWR cannot be repeated then use the INDUCTOR switch to increase the inductance by one swi...
Page 11: ...323 0549 or the MFJ Factory at 662 323 5869 You will be best helped if you have your unit manual and all information on your station handy so you can answer any questions the technicians may ask You...
Page 12: ...USER NOTES...
