Ok, here is one of many sites that have instructions on winding the transformer:
PD7MAA HOMEPAGE: Multiband end fed antennas 3.5 - 30mHz
The antenna is a resonant end fed half wave at the design frequency and will operate on even harmonics. The transformer matches 50 ohm coax to the approximate 3,200 ohms of an end fed half wave with very little loss. Once you make the transformer you cut 1/2 wavelength of wire plus a little for trimming then tune the antenna for the best match by adjusting the wire length. If you make it about 16ft long or a half wavelength on CB it will have a great match on CB and at 54Mhz and so on. If you make it about 36ft long or a full wavelength CB it will also work great on 13.5Mhz and 54Mhz and so on.
I use various versions of this antenna all the time for 80 through 10m amateur and I set up a friend with a 10m version (basically the same for CB) with 1/2 wavelength of wire for 28.5Mhz (about 16.5ft of wire) and hung the whole thing vertical from a 33ft telescoping fiberglass mast. Compared to the 7ft, 10m Hustler antenna on his truck, the end fed half wave was about a full S unit stronger to everyone and would work about the same as an Antron99 or similar under the same conditions. And you can build it for a couple of bucks.
Anyway, you need to decide on the power level then purchase an appropriate ferrite core. You will also need some wire, preferably 20 to 16ga enameled magnet wire for a 100w version and 16 to 14ga is good for a higher power one. I switched to Teflon insulated wire for the transformer but its a PIA to wind and keep on the core because it really wants to unwind. You have to Ty-rap it down as you wind that stuff.
Here is a good place to buy the ferrite but you can also find it on Ebay. For low power and up to 100w SSB you can use a tiny FT-114-43 core available here:
FT-114-43 - Amidon
Or for a little heavier duty version this core is twice as thick and is what I now use for 100w SSB versions:
FT-114A-43 - Amidon
For up to about 400w SSB you can use this core:
FT-240-43 - Amidon
To wind the transformer you need to have a twisted pair for the primary and you cut maybe 4ft of wire for a small core or 6-8ft for a large one and fold back about 18" of wire on itself, hold the first few inches of the fold with some Vice Grips and twist the 18" long piece with 18" of the longer one until you have a few inches of the original 18" wire that's not twisted.
Then stick the twisted section through the ferrite core until split the junction of the long and 18" wire is flush with the outer edge of the ferrite core. The section you pushed through the core is the first of two turns for the twisted pair primary, so as your holding the core flat in front of you, wrap the twisted pair around the core back toward you to the right of where it started and stick the end of the twisted pair through the center of the core again and wrap it back around so it exits away from the core and parallel to the split junction of the long wire and 18" wire.
The now longer twisted pair with the bend at the end and sticking out from the core will be cut to reach a coax connector and that will go to ground. The short but exposed part of the 18" wire at the junction of the 18" wire and long wire is the 50 ohm input and will go to the center pin of the coax connector.
Look at the diagram and pictures in the link and continue wrapping 6 turns of the long wire around the core to the left of the primary windings. Every time the wire passes through the center is considered one turn. I prefer to push the core side of the wire through the hole in the core then pull the remaining length through rather than sticking the end through the hole and pulling the entire length. You get tighter windings against the core that way.
As you can see in the link picture, after 6 turns, you cross over the core and continue with 7 more turns. The cross over is considered a turn so when you are done the transformer should have two turns of twisted pair for the primary and 14 turns for the secondary. The end of the secondary at the 14th turn is where you attach the 1/2 wavelength of wire.
You will need a ceramic disc or dipped silver mica capacitor anywhere between 100pf and 150pf across the 50 ohm input and the voltage rating can be 100v for a stock CB or maybe 1kV raging for a 400w version. For 100w versions I usually get 500V dipped silver micas around 120pf on Ebay cheap.
Attached is a picture of an 800w version I made using dual 2.4" cores so you can see the windings and how I put them in boxes. This one seems to be missing a secondary turn and I forget why but it works great. A 100w version can fit in a tiny enclosure made for key fobs and I usually use a BNC connector on those because the box is so small.
Jotting all this down seems like work to me so I'll stop here and hopefully this gets you going on the project. One day I'll just whip one together with a camera running and put it on Youtube.
prcguy
That sounds awsome.. I bought my balun from a guy on ebay from Michigan. Very well built, I really want to try skip out that's why I bought a Galaxy and a ssb radio.
