Menu
- About
- Ham Radio
- NL SwapShop
- NL SOTA Association
- 3D Models
- Linux
- Raspberry Pi
- Windows
- Software
- Photo Gallery
- Contact
- Search

Long Wire Antenna With 9-1 Balun
Using T200-2 Torroid
I made a 9-1 before and wanted another for another location / portable use. If you have a T106-2 or a T130-2 Click Here to view that how to guide. This page is for the T200-2 torroid as well as the 3d printed box for it.
You will need the following items to make the antenna
1 plastic enclosure to hold the toroid ...unless you want to 3d print the design I have below
1 powdered iron toroid T200-2
3 approx 20" pieces of 22 AWG solid insulated copper wire (ideally different colors)
2 bolts with nuts to hold wire to case
2 ring wire lugs
2 wing nut
1 SO-239 panel mount connector to connect the antenna to your radio
Misc bolts / screws for so-239 and to hold the cover to box
You also need antenna wire....longer is better but avoid having a length that is 1/2 wave or any
multiple of for a band you want to operate. As a general guide use:
29, 35.5, 41, 58, 71, 84, 107, 119, 148, 203, 347, 407, 423 foot lengths.
If you can go longer great...just stay away from 1/2 wave lengths.
Now to work on the toroid...this is critical to get right. Take your time and make
sure all the windings are tight around the toroid and use the pictures for
guidance
Wind the three 20" pieces of insulated solid wire onto the toroid. Place the wires as
shown blue-red-yellow, and wrap the wire around the toroid as shown below. Follow the schematic
below as your guide. I didnt have different colored wire available, if you are in the same situation
as well...you can construct it no differently ...just be very careful on soldering the right wires together.

If you want to use the 3D model I did you can DOWNLOAD
THE DESIGN AND STL FILES HERE. This will give you a 3d printable box and cover as shown below


Once you have everything in place and mounted and soldered your project should look like the following. Placement inside the box for the mounting
is not critical but try to keep the leads as short as possible.





I used some hot glue to secure everything in place... althought the cover has columns protruding
into the case to hold the torroid in place. I used some clear silicone (make sure its not conductive) to seal up
the project box to secure everything from rain and the other elements.