Re: Type 2 PHSNA Transformer T1 replacement

Steven Dick
 

I put a file called "Type II PHSNA transformer comparison" in the Files section in the K1RF folder.  I tested various transformers with a Rig Expert antenna analyzer. In summary, the Coilcraft WB1-6TSLB worked the best followed by a bifilar-wound FT37-43 toroid, while the standard wound FT37-43 toroid was substantially worse than the other two.  If you wind your own on an FT37-43 toroid, I would recommend winding it with bifilar-wound primary and secondary (I.E. 12 turn twisted pair with a center tap on one of the wires).  If you are using a AD9851 for high frequency operation, I would strongly recommend using a commercial wideband center tapped transformer such as the Mini-circuits T1-1T or a Coilcraft WB1-6TSB.

Regards,
"Digital Steve", K1RF

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