50 ohm to 200 ohm RF transformer measurements 06.09.2004 OH7SV
These HF wide band transformers are designed and tested for low power (1W) mosfet power amplifier input and output circuits.
The used core is Ferroxcube MHB2-13/8/8-4B1 dual hole ferrite, u=250, AL=0.5uH/turn.

Simple wire wrap transformer. Primary 4 and secondary 8 turns

Blue initial secondary connection, pink secondary polarity changed

Bifilar 4+4 turns twisted pair 0.25mm enamelled cu wire

Primary and secondary polarities not possible to change 

Trifilar 4+4+4 turns twisted 0.25mm enamelled cu wire

Blue initial primary connection, pink primary polarity changed

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