Common Mode Current with MFJ-854

FT140-43 7 Turn Balun measurements
14MHz Inverted-V at 25' AGL
25' Type RG-8X feedline
MFJ-854 Current Meter, Calibration Charts
Eight 17' On Ground Radials

Power versus Common Mode Current
Measurement Verification Plot

50W TL Length vs CMC
Length Wave Length CMC mA
26.3' 0.374 43
34.1' 0.485 32
35.4' 0.504 32

50W TL Length vs CMC
Length	Wave Length	CMC mA
26.3'	0.374	43
34.1'	0.485	32
35.4'	0.504	32

Test Description

Radials and Current Meter

EZNEC Balun FT140-43 7T

VNWA S21 Through Z Measurement

EZNEC Model

EZNEC Model Wire 6 = 0.01985 = -34dB
Minimum plotted current = 0.018 = -35dB
CMR Fixture measurement = -37dB Reference

TL Length versus EZNEC Current

Flawed CMC measurements

using Homebrew, without shielding, current meter

Antenna Common Mode Current Test

Balun and Antenna

TL = 25'
EZNEC Wire 6 current = 34mA
50W, 1A Measured current = 16mA
100W, 1.4A Measured current = 30mA

TL = 25'
EZNEC Wire 6 current = 34mA
50W, 1A Measured current = 16mA
100W, 1.4A Measured current = 30mA

TL = 34'
EZNEC Wire 6 current = 22mA
50W, 1A Measured current = 16mA
100W, 1.4A Measured current = 30mA

TL = 34'
EZNEC Wire 6 current = 22mA
50W, 1A Measured current = 16mA
100W, 1.4A Measured current = 30mA

Transmitter and Amp Meter