The Dollar Match has come in very handy when installing a Hustler or Bandspanner HF Antenna for mobile use. This Un-Un was regularly constructed by Nico ZS4N and the booming signal that he puts out on HF mobile is testimony that this transformer is a real winner.
1. Toroid size (not crucial) and enclosed sketch.
Diameter = A = 38 - 40 mm
Thickness = B = 8mm
Inside Measurement = C = 24.5mm
Height = D = 15mm
A T150-2 or T200-2 Iron Powder Toroid is recommended.
2. Length of copper wire: +- 2 meter divided into 3 sections
3. Thickness of wire: 1 mm. Thinner wire can also be used which will work easier.
4. Take three equal length sections and mark die opposite sides 1 - 3. You can straighten the wire by putting one side in a vice and the other in you battery powered drill. Give just enough power to straighten the wires.
5. Thread die winded piece of wire 5 x through the toroid. Start at the bottom and end with the last turn at the top of the toroid i.o.w. start and end at the same end.
6. You now have 6 wire points that is marked 1,2,3 and 1.2.3. Attach as follow:
6.1 No 1 on the right is the feeding point from the radio and coax braid goes to the ground point as shown in the diagram. No 1 on the left is cross connected with wire No 2 right. No 1 on the left is the the outgoing point to the antenna with RG58 cu.
6.2 No 3 on the right is cross connected to point No 2 left.
6.3 Point No 3 left is the ground point for the input and output points of the Coax cable.
7. Diagram of the Un-Un Transformer
(Click on images for larger view.)
