On Dec 24, 9:34*am, Wimpie wrote:
On 24 dic, 03:15, JIMMIE wrote:

I want to contruct a 4:1 BalUn but instead of stepping the impedance
up from 50 to 200 I want to step it down from 50 to 12.5. Is there any
difference in design between the two.

Jimmie

Hello Jimmie,

It depends on the design.

In case of a classical transformer, it will be the same, except that
the inductance can be divided by 4. Practically this means you can
half the number of turns.

For example if the 200 Ohms side have 8 turns, you can reduce this to
4 and this will be the 50 Ohms side. *As current increases (with same
power), you may use thicker wire, or use two windings in parallel.

In case of a real transmission line transformer, you may need
transmission lines with unpractical low characteristic impedance.
Maybe you can provide some details about the type of balun you want to
make.

Best regards,

Wim
PA3DJSwww.tetech.nl
without abc, PM will reach me very likely.

I had thought about the increased current and decided the best way to
compensate for this may be to use a transformer designed for more
power than I had palnned on using As I am only going to be running
100W PEP I figure using a design for 1000W would be more than
sufficent. I had not considered the need for fewer turns. Is this
important?

Jimmie