ozQRP MDT Construction Manual page 28

Step 15: Coils
Count turns on the inside of the toroid. A turn is considered to be counted when a wire passes
through the center hole.
Transformer T1
Take a 120 mm length of 0.4mm
enamelled copper wire. Wind 4 turns on a
FT37-43 ferrite toroid. This is winding 1.
Take a 180 mm length of 0.4mm
enamelled copper wire. Wind 8 turns on
the ferrite toroid. This is winding 2.
Take a 120 mm length of 0.4mm
enamelled copper wire. Wind 4 turns on
the ferrite toroid. This is winding 3.
Scrape the enamel off the ends of the
wires and tin with solder before installing
in the PCB.
The winding direction is not important.
Transformers T2
Take a 180mm length of 0.4mm enamelled
copper wire and wind the 8 turn primary
on a FT37-43 ferrite toroid.
Take a 90mm length of 0.4mm enamelled
copper wire and wind the 2 turn
secondary.
Scrape the enamel off the ends of the
wires and tin with solder before installing
in the PCB.
The winding direction is not important.
MDT Construction Manual – Issue 2 Page 28