MFJ MFJ-213 - Checking HF Baluns

MFJ-213 HF/VHF/UHF Antenna Analyzer Instruction Manual
7.8 Checking HF Baluns
A well-designed balun will have low SWR and good balance over its
operating range. The MFJ-213 can test both of these qualities using the setup
shown below. Configure the unit to operate in Analyzer mode in the HF
range. Connect the input (unbalanced) side of the balun to the analyzer’s
antenna connector. Connect a center-tapped resistive load to the balanced
side (R1,R2 = 25Q for 1:1 baluns, R1,R2 = 100Q for 4:1 baluns). Using the
Tune and Band controls:
(1.) Sweep the balun for SWR with the test lead disconnected from the load.
(2.) Connect the test lead to the mid-point (A) and re-sweep. There should be
minimal change.
(3.) Connect it to either side (B) (C). SWR will go up, but should go up
equally on both sides.
Short Test Lead
MF-213
Version 1 15 © 2012 MFI Enterprises, Inc