Topband: Transformer Question

Ford Peterson ford@cmgate.com
Fri, 4 Jan 2002 16:33:17 -0600


I need to know if there is a correct solution to transforming complex
impedances.

Assume a perfect 4:1 transformer at 1.83MHz.  A load with R+/-j of 260 +330j
I am fairly certain that the R term just divides down to ~65ohms
(260/4=65).  What happens with the j term?

To tune out the 330 ohms, a 264pf series capacitor is in order.  If the j
term divides down to 82.5j, then a capacitor on the input side of 1000pf is
in order.  If I had to choose, the 1000pf is less lossy and would be best
placed on the input side of the transformer.  Right?  Or am I missing
something...

Thanks for the feedback in advance.

Ford-N0FP
ford@cmgate.com