[TinCanAlley]

Originally Posted by N2IXK

The waveform looks to be about 1.5 divisions peak to peak, so that could be either 7.5V or 75V, depending on whether or not the "5V/div" is taking the 10:1 probe into consideration.

75 vpp ripple on a 240V supply is a problem. 7.5V, not so much.

The doubled waveforms might be caused by improper triggering. Make sure you are triggering on whatever channel the probe is connected to, and if your scope has a TVH trigger mode, use it. Try rocking the trigger level back and forth around zero, and see if that makes the trace clearer.

I would start with the same value cap as you already have installed, and putting it right in parallel should be fine if it actually goes to ground. The attachment isn't showing up for me...

The probe was in the 10x mode. Also, the triggering is from a Leader LCG-396 Pattern Generator.

The cap is connected the following way. There's a lead from the flyback to a leg of a diode, the other leg of the diode connects to a leg of a 150 ohm 2W, the other leg of the resistor goes to the positive side of the cap and a lead that connects the 240V around the chassis and finally the cap goes to ground.

I'll have to find a local source for a 10uf 300V cap. The local Radio Shack doesn't have them in-store. Must be a place around here somewhere. Not looking forward to paying 7 bucks for shipping of a single cap.