Thank you Hans.
After reading the doc I take it that the improvement for low band units is not significant enough to warrant replacing the original type of transformer, yes?
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Hi all
Many thanks to Ross EX0AA for his transformer designs, the 3:3 ratio (9V operation) WTST (Weird Twisted Sisters Transformer) and 3:2 ratio (12V operation) RWTST (Really Weird Twisted Sisters Transformer).?
I have now uploaded documentation for both these designs and the original simple design, all in one document which is referenced from the QMX, QDX and QDX-M assembly manuals.?
The original purpose of the designs was to solve the parasitic resonance problem that sometimes reduced output power on 10m band on the high-bands QDX. However the improved symmetry and tighter coupling of these transformers does improve performance (put power, efficiency, suppression of even harmonics) on all versions of QMX, QDX and QDX-M. Therefore the twisted wire transformers are now the recommended build for all these transceiver kits.?
The transformer instructions are linked from each of the QMX, QDX and QDX-M pages. I removed the transformer instructions from the respective assembly manuals. So you will have to use the transformer document and choose the appropriate transformer (WTST for 9V, RWTST for 12V supply operation.?
