Firstly, I want to say that in Türkiye, a large number of amateurs use this Pink toroid but there is no number, sign or specs about it.
We just say "Pink Toroid" and we buy. It is about 5-6TL.($3)
I made some measurements and i guess Al value is approx. 12000.
We use this from MF to 30MHz and there is no problem. What a magical toroid, huh? hihi
Mount So239 and banana sockets to the box.
We use 1.2mm wire and wind 17 tight turns on toroid. When you finish between wires, wind 17 turns same as first.
Using a multimeter or tracking by hand find which wire is on first winding which is on the second.
Using a knive or orter tool, clean the paint on the wire and solder first windings output to second windings input.
You should have a 34 turn winding and if you test the continuity of free ends, you must see short.
When you finish winding get 2 or 4 cable ties and secure windings as shown as last picture. 2 above, 2 below, 2 above, 2 below...
Solder soldered 2 wires at the center to the so239's ground(chasis).
Solder one of ends to one banana socket.
Solder other end to other banana socket with center of so239.
Close the box. Check connections with multimeter. You must see short circuit between all terminals.
Connect dummy load or wires and test it with real rf.
If you wish, you can fill it with silicone, epoxy etc. I didn't use because 4 piece of 1.2mm wire can hold the toroid secure enough.
