Definition: Current Balun, Voltage Balun

Readers of (How) does this balun work? have asked about the meaning of the terms Current Balun and Voltage Balun. The following is a cut and paste from my old site.

Definition: Current Balun, Voltage Balun

The terms Current Balun and Voltage Balun are often used. This article explains the key characteristics that determine which best describes a particular balun. The approach taken is to charaterise a balun because of how it behaves externally rather than the internal implementation. Continue reading Definition: Current Balun, Voltage Balun

Last update: 5th June, 2014, 10:38 AM

A QRP small transmitting loop evaluation

The ‘net abounds with articles describing easy to build low cost small transmitting loops (STL).

This article describes measurement of a STL for 4MHz using RG213 coaxial cable for the main loop and its tuning capacitance, and a smaller plain wire loop for transformation to 50Ω. Continue reading A QRP small transmitting loop evaluation

Last update: 7th April, 2017, 9:10 AM

ARRL Antenna Book 21 on small transmitting loops

The ARRL Antenna Book 21 (Straw 2007) gives equations and advice for design of small transmitting loops.

Many Hams have used these formulas and method for their designs, and some have even produced design tools (online calculators and spreadsheets) implementing these formulas.

This article reviews these formulas and advice. Continue reading ARRL Antenna Book 21 on small transmitting loops

Last update: 17th April, 2015, 7:07 AM

OCF dipoles

Off centre fed (OCF) dipoles are very popular with Hams on HF.

Many claims are made for variations of the theme, but the essential common feature is that the offset feed point provides a feed point impedance that is not too unsuited to 50Ω coaxial feed line at the fundamental resonance of the dipole and half wave harmonics. Continue reading OCF dipoles

Last update: 1st October, 2015, 8:54 AM