[AdrianH]

It is one of the Ebay units that give 150 to around 400 Volts and DC for heaters from 12 Volts, all switch mode style buck inverters. if you search Ebay for 'Amp/ Preamp/ Filament DC 12V to 150V-420V DC High Voltage Power PSU Board f Tube' These are sub £15 so should be OK for import duties I think if you only get one.

I also have another style I can use which is just HV, these can be found with 'DC-DC 45-390V High Voltage ZVS Boost Converter Step-up Booster Module' again for around £10 each no heater volts on this.

I used then, when I started playing not having suitable transformers to make up a PSU, and I hate the idea of rectified mains.

For the valves I have many which are TV valves with higher volt heaters I will probably use my variable DC power supply for heaters and use one of the above for HT.

I have found in the bits box a NMS1215SC which is 12 Volts DC to isolated 30 Volts out, so I can further regulate with a Zener to give me a grid bias down to -15 Volts. Or two 9 Volt PP3 batteries and a Zener?

I now have to wait for a replacement Voltmeter as I knackered one on the unit last night trying to stop the needle sticking, the meter must have been dropped at some time.

Adrian