Question about voltage for detector valve

[Ed_Dinning]

Hi Nick, these detectors are often run at 90 volts, but if you get better control of reaction it is OK to go lower. The valve does actually have a very small amount of bias from the filament connection. This is why it is important to connect Fil + and Fil - in the correct sense.

Ed

[SurreyNick]

I will keep that in mind Ed. Thank you.
Nick

[Murphyv310]

Hi Nick.
My intention was to draw out some circuits of the sets I've made with the Russian valves. I've just had no time and getting into the shed has been a little tricky.
Basically I have been using 1X18b valves for detector and audio preamp. For the filament I have used a "C" cell and a 25 ohm potentiometer to adjust the filament for 1.1-1.2 volts. Oddly with these valves the anode is not the best electrode for operating the valve in triode mode, using the G2 is perfect and you can then strap the anode to it if desired, it makes no difference to performance though.
For output I use 1X29b valves, it has a centre tapped filament and I connect them up for parallel configuration. I connect the valve up as a pentode and the output then is taken from the Anode, the G2 can be fed from a 47k resistor as current drain is tiny on the G2 on these valves, the screen and G3 of the valve is taken to the centre tap of the filaments.
These little valves will work a treat on your little circuit and will give an output at an HT as low as 18 volts.

They are great little valves for experimenting with and I'm about to embark on an FM radio project using Super-regen, not sure if it will work but I don't really see why not.

I'll still try to draw out a couple of circuits but I do it the old way with pen and paper.

[AlanBeckett]

Press on 310, as I've got some to play with as well.

A;an