Picture:

Schematic:

Input: 3 transmission lines with an impedance of 150 ohms in parallel = 50 Ohms,
Output: 3 transmission lines with an impedance of 150 ohms in series = 450 Ohms.
Picture input Picture Output


Impedance of a transmission line:

Formula:
Impedance = 276 log (2D/d)
Wire diameter (d) = 0.9 mm
Distance (D)= 1.58 mm
To achieve 150 Ohms, you have to tune de distance between de two wires.
This will give you a good return loss result.
Measuring results:
- Return loss:



- Insertion loss:
Picture:

Insertion loss is for two devices!


Insertion loss is for two devices!

Return loss of this steup:

What toroids did you use? And the mixture?