small valves and RE: OT

1R5 = DK91 == Pentagrid changer 1U5 = DAF92 == Detector and 1st audio 1T4 = DF91 == IF amplifier 3V5 isn't in the equivalents book, but 3V4 = DL94 == audio output And of course the 117Z4 is a rectifier with a 117V filament. The signal valves have the filaments as I described in my last message (i.e. 1.5V each apart from the output which is 3V centre-tapped). A battery-mains set would nrarly always have them in series (on mains, they're fed via a dropping resistor from the B+ line, putting the filaments in series reduces the dissipation in that resistor). That explains the 7.5V part of the battery. The 1.5V part is still a mystery. It could well be bias for the audio output valve, but what the heck does it do on mains? self-bais on mains only. I could _just_ believe that. I am sure I don't need to warn you about this, but it's almost certainly a live chassis set when run off the mains. I know the feeling, although doing it while the set is still working would allow you to note down valve electrode voltages, etc. No why on eart hwould oyu want to do that??? [Elektor] Oddly we can get Nuts and Volts and more usefully Circuit Cellar in shops in the UK... IMHO Circuit Cellar has really gone down over the last year or so, it seems to be just yet-another-microcontroller-circuit now, and quite often the microcontroller picked doesn't seem to be the most appropriate device .Oh well... -tony