08 February 2016

ELECRAFT BL2 Balun Measurements

The ELECRAFT BL2 BALUN Return Loss and Balance were measured as shown in the referenced links. The Balance measurements were performed according to W7EL's referenced document. Refer to pg 163 paragraph named 'Current Balun'.

Elecraft BL2 BALUN Specifications & Operating Manual

BALUNS. What they do and how they do it. W7EL

Test Configurations and BALUN Schematic

Return Loss Measurements

Balance Measurements

Test Fixture 1

Test Fixture 2

Test Fixture 3


  1. Dick thanks for those results. I'd be interested in seeing what losses the balun presents when it's operated well outside of standard impedance since I think many hams will use this with a multi-band antenna they are likely to be driving it at impedance as much as 10:1 from 50ohm.

    Rich AA4OO

  2. Thanks for the comment Richard. I for one, am completely confused as to why one would operate a BALUN well outside the impedance specification that it is built, designed and specified for. I am aware that this is the practice amongst many hams, especially when running a doublet into a balanced feeder. I suggest that better practice is to deploy a balanced ATU for this configuration. This will cancel out reactances and allow the presentation of the correct a resistive load to the BALUN thereafter.