MFJ MFJ-249 - Page 17

MFJ-249 SWR Analyzer Instruction Manual
Testing RF Chokes
Large RF chokes usually have frequencies where the distributed capacitance and inductance
form a low impedance series resonance. The troublesome series resonance can be detected by
slowly sweeping the frequency of the MFJ-249 over the operating range of the choke. Peaks
in the voltage measured by the RF voltmeter will identify the lc w impedance series-resonant
frequencies.
choke 1N34
To the MFJ-249's. ( S
"ANTENNA" Bees
connector
“\.
Measure
the
voltage
= 01 between these points
7. with a Hi-Z meter
*®
a
All leads should be short
Refer to the section on measuring the inductance of RF chokes o:: page 13.