Georg,

If you transform a 20VAC signal from a 50 ohm source into a 250VAC signal,
the 250VAC output will be at an impedance of about 7,800 ohms (conservation
of energy; Po = Pin). At this high impedance you won't be able to drive
virtually any length of coax, even open-circuited, as just a few tens of pF
of cable capacitance will cause a significant rolloff at 2 MHz. What load
impedance do you intend to drive?

BTW, 20Vpp at 50 ohms out of your 'signal generator' is quite a signal -
about 1 watt. Is this really the case?

Joe
W3JDR


"Georg Holderied" wrote in message
...
I need to build a transformer that transforms the output of a signal
generator (0.5-2 Mhz 0-20Vpp into 50 ohms) into two opposite phases
at 0-250V.

Load is a few picofarads and a short length of shielded cable.

Where can I find formulas for winding such a transformer ?

Is it preferable to build it as an air or on a ferrite core ?

What ferrite material would I use ?

BTW the signal is used for driving multipole ion traps.

I am an electrical engineer but have not much experience with RF.

George