Jun 21, 2017 · I get lots of questions about baluns. This video explores baluns and gives demos. A balun is a device to convert a balanced transmission line to an unbalanced transmission line and vice versa ...

Sep 14, 2015 · A Super J-Pole Antenna for the 70Mhz (4m) Amateur band. The Vortex ‘Super J-Pole’ Antenna consists of a five eighth wave vertical radiator, a half wave tuning section and a half wave top section. At the base, a quarter wave matching stub forms the classic ‘J Shape’. Forget you ever heard the term "choke balun". I'm sure you know balun stands for BALanced to UNbalanced. A 1 : 1 balun can be used to match a coax to an equal value impedance, balanced line. A simple choke (one to eliminate common mode currents - CMCS) can be made by winding 25 feet of coax around a one gallon ice cream container. Sep 24, 2018 · Bought a commercially made 2/70 J pole which was dead cheap, common sense told me to isolate this from the mast just like you would not allow an antenna to touch another piece of conducting materiel, I used a modified plastic bottle as a shief followed by an air choke ( standard) hey presto, works as good if not better then my more expensive colinear vertical I had up previously.