I needed a quick project and a small balun for my SDR radio and various portable radios. Also something I could use for the FT-817, KX-3 QRP use out in the field. This little guy did the trick. Its a small little 2 x 1.5 inches little marvel of a 450 ohm balun.
I have had great success with it on 40m-10m using 29 feet of wire. Performance seems better with a 15 foot ground wire if you do not have at least 16 feet of coax.
I get my Toroids from Earl at Netty Electronics
So its a T106-2 red with 9 turns #22 wire which could handle 100 watts of power but my use in 50w and under for portable/field work or for reception purposes.
See my other post on the Marconi End Fed NVIS antenna as this little guy could be pretty stealthy with some black #26 silky wire and fit in a shirt pocket.
Here is a schematic of the little pal