Found this so thought it might interest those looking for ways to attain HT from low DCV http://uzzors2k.4hv.org/index.php?page= ... tconverter
After devoting a whole arvo rummaging around all the scrap circuit boards I keep in the shed I finally found enough parts to bench test.
Running from a 500mA 12VDC Plugpak I'm getting steady output from 220 VDC up to 290 VDC.
This Has been running for a few hours with a light load,,Nothing getting hot.
Times like this a scope and all the fancy tecky tools would tell me more but hey if it works then why spend money only to see squiggly lines.
My AM Radio above my bench tells me it's a very dirty output but Removal of the Led reduces the noise a lot so I'd guess it might not be needed.
So far so good. Now I'll have to find some valvey stuff to see if it actually delivers in a real circuit.
I did find a 100uH slug inductor in my junk but that did get quite warm.
So I swapped it with a larger donut unit and this also got hot.
Finally found another slug with 150uH reading and this one runs cold.
I changed some of the FBack values to bring the voltage range back down to sane levels.
This can easy output much higher voltage but I don't have the need and triodes only need around 200 Volts to work well.
I already have a 240 VDC booster circuit running a very quite AX7 preamp but it is rather bulky and this would be a lot smaller.
I'll post my altered circuit if Anyone interested.
Have fun,, Phil.