Good morning Telamon,

Telamon wrote:
The impedance ratio of your transformer is 50 ohms to 800 ohms.

p= primary
s=secondary

Turns p/Turns s = the square root of (impedance p / impedance s)
so
2/8= square root(50/s)
800 = s

The turns ratio is 1:4 and the impedance ratio is 1:16. In other words
the impedance ratio is the square of the turns ratio. This is a little
high and I would go for more like turns ratio 1:3 for impedance ratio
of 1:9, which would be 50 ohms : 450 ohms. For example you could use 3
turns primary and 9 turns secondary.

Thanks for the formula...

The sloping wire characteristic impedance will change with the height
above ground so I expect that you would want an impedance number at the
coax/wire junction.

You mean that the impedance of the core will depend on its altitude ?

The core will have a frequency range it will work over so test it at
three places. Test it at the lowest, highest and some place in the
middle of the intended frequency range. You may find the response falls
off on the low or the high end. When you do this wind the primary and
secondary apart from each other so you get the core response.

When you are done testing the core range wind them together so the two
windings couple better enhancing whatever coupling the core is
providing for you.

Thanks, I will try that...

Charly