Welcome to the next edition, for 2004, of the "Ragchewer". Looks like the Hurricane Season is dealing the SouthEast United States with plenty of rain and wind. The time to get ready for bad storms is not a day or two before the storm gets there. Rather, one should be looking at the home situation, personal as well as Amateur Radio, at the start of the bad weather season. I guess that it is human nature to procrastinate until the last minute. Anyhow, links to check lists for preparing for bad weather can be found in the Amateur Radio Emergency Service (ARES) section of this Website.

Project - Winding your own HF BALUN Transformers
by Tom, N4FWD

1.  For this project, you will need a powder Iron toroid core, Type FT-240-67, and 14 gage house wire. The core can be gotten at a hamfest or ordered from several vendors, See Links Page of this Website - under Parts. The house wire can be purchased from a DIY Home improvement store, like Home Depot or Lowes here in the USA. You will need to cut two pieces of wire about 30 inches long (about 76 cm).
   
2.  Wind about 10 to 11 turns around the core using wide spacing.
   
3.  The next winding will be done in the bifilar method. Carefully lay the next wire along side the first one always maintaining the same relationship between the two windings.
   
4.  Depending on the type of transformation which you desire, the windings will be connected differently.
   Four to One BALUN  Note that the center connection is grounded to the SO239 shell.
   Four to One Unbalanced to Unbalanced  Note that the SO239 shell, one leg of the ladder line, and one side of the toroid windings are all connected. The advantage of UN-UN connections is the ability to easily add additional windings for higher transformations. Add a third winding for 9 to 1; Add a fourth winding for 16 to 1.
   One to One Current BALUN The first two tranformations are for Voltage arrangement. This next one is for equalizing the currents going into a balanced antenna.

For questions or comments about this site, contact N4DYR.
Copyright © 2004, West Georgia Amateur Radio Society
Updated:  09/27/2004