[HomeBrew] inverter circuit

[WB6BLV]

anyone on the reflector have a diagram for a transistorized
inverter to step 12 volts DC up to 280 DC for plate supply
for small transmitters?  i used to build a lot of them, but with
newer technology perhaps some of you have a fav design that
uses transistors to replace the vibrator found in many inverters,
so the DC is changed to AC which is stepped up by a transformer.,
then rectified back to DC at higher voltage but lower current.

Some circuits even use a 555 chip to drive a power transistor in
primary of step up transformer.

I think i want to avoid switching power supply at this time

Thanks

John