5FP7 project starting with the focusing coil.

[AdrianPH]

Last night I finished adding a second stage EF91 to reverse the MT sawtooth, basically the same circuit that would normally drive an electrostatic CRO symmetrically, but with a change of capacitor values I have reduced the output of the waveform to approx a 50 Volt peak, it may also provide a little bit less loading on the first stage.  The sawtooth is a bit jittery which I believe is down to the cheap 1nF Blue Caps I have used in the circuit.  I seem to remember that happening in the TV circuit originally and replacement with some decent Silva-mica ones should stop that, I hope.

Next step will be to add the EL84 valve and components to drive the transformer and keep my fingers crossed it will work driving the scan coil.

           

Not the neatest layout and still all driven by DC buck units yet.

Adrian