Transformer coupling question

I have a nice toroid transformer oscillator that works from about 600mV supply and up; very ligit load; made with two transistors, collectors drive CT primary with 10 turns each side and 3 turns feedback to the bases (biased with 4.1K to supply).
The output waveform looks like a square wave but has definite overshoot on each edge and a little droop; did not measure the frequency; the toroids are made with some kind of powder ferrite.
Ten turn secondary to a FWB gives about 450mV at 600mV supply, about 1.6V at 1V supply and about 5.5V at 3V supply.
What i want to do is run a common "driving" secondary winding from this toroid oscillator to three or so other toroids (same size and type) that each has ten turn secondaries and that FWB load (1meg, 0.1uF).
Do i need to put a resistor in series with that "driving" winding to prevent excessive loading, and is it OK to use one turn for that or better to use ten turns?
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