The two MOT's in series 240 Volt AC input, each transformer receives half the mains voltage. This impacts the secondary windings, I needed at least 18 Volts from the secondary windings. Each secondary gives 9 Volts AC or just over that. 14 AWG is as heavy as I could go, only because of area for winding the cable on. The no load temperature is around 48°C fluctuating with what the rooms ambient temperature is. I think I understand the AC capacitor theory, and I'm keen to try it, two MOT's in series for a high current low voltage works very well, my current radio set up has been using this series MOT power supply for over 6 months. It on 24/7 no problems at all, just the added weight of that second transformer so they function with out overheating. The unit has fans, but there only on when the PSU is working heavily. The cable I rewound the transformers with was silicone insulation sheathing. I used a blunt round nose follower, like a marlin spike but rounded polished end to get more turns on, silicone spray made it relatively easy to get the extra turns on. A few years ago I did try splitting the IE core, but once reassembled the no load current was worse than 3 Amps idle, some how it must of upset the magnetic circuit. I did think the welds equalled a shorted turn, I did realise the shallow depth loop it created, I know these things aren't perfect, but the price of high VA transformers is rediculous. And the MOT transformers to me where free, I only had to buy the secondary cable. The unit in use is in the picture below, the two transformers and bridge rectifier are in the lower half of that power supply. Everything else is in the top half of these two cases bolted together. It's very heavy, I did weight it, 10 to 12 KG from memory. That's why I'm chasing a single MOT variant.