help me drive a flyback!

hi, i started this with the circuit from these folk,
POWERLABS' High Voltage Solid State Flyback Driver
it flew nicely after i switched the base and the emitter round,

after messin round i found that i could ring it up with the transistor base hooked to my signal generator finding that it rang quite well on several various frequencies.

i also found that by moveing collector (and the 12v vcc lead) from the primary flyback coil to the secondary(feedback) coil,useing it as an input the transf reached much higher voltages with much greater efficency,
with a constant 12vDC to charge the coil
when i set the scope to 200khz@5v the flyback responds with a 2" spark, an a current draw of +700mA
bringing up the scope to ≈400khz@5v the flyback responded with a insaine kick, at least triple the sparklength but with a current draw of only 70mA

so now im trying to get it off the generator and on to a DC clk of some sort, however iv used both 555 timeing and hex inverters to try and clock this thing, however my clocks are destableiseing? and not holding the signal proper to drive the 2n3055 the way the signal generator can(does)
i need a clk that can go frm 2.5-7.5v and from 400khz - 440khz
, any ideas??

This type of circuit does not have any timing components and relies on the inductance of the transformer to produce a time-delay and thus a frequency of operation.
The first thing you can do is put a 100n between base and ground to make the circuit more efficient.
You must keep the output loaded, otherwise you will damage the transistor via spikes.

**broken link removed**

now when you say loaded, that means i can keep the HV lead open in the air right, and just can't run it to ground right?
what about discharging a spark, is that OK?< I know that when a spark discharges it has 0 resistance,

also :

1) would it help to put a diode across the primary winding in parallel to protect the transistor, like with a relay??

2) OR if i put a diode on the ground of that second capacitor, would that protect from over surges?