Tube with low filament current??

Hello,
I need a miniature dual triode type tube like the size of ECC83, but one which uses low filament current. 300mA is too high. the lowest the better.

Do you know of any types?

You must search between battery powered tubes like here:

http://www.fourwater.com/files/batradio.txt

If only current is important then search between UCC8x series tubes. They have 100mA filament current.

Tube series with filament data are here:

http://www.duncanamps.com/technical/tubenumber.html

I guess, you are actually looking for low filament power. Then Uxx series tubes don't offer a benefit over Exx series. The required filament power is mainly defined by the cathode surface area, so only miniature tubes dedicated to battery operation offer considerable power reduction.

I fear, unlike for standard types, that are still manufactured in small quantities, the supply of these types will be rather poor.

FvM you are right. The same size of cathode requires the same filament power. Low filament power tubes are battery powered tubes with Uf of about 1.4V. This is type D or american tubes with 1 in front of letter and nuvistors.
On audio DIY forum the same question was asked?

Your best bet would be "light house" tubes as used in TV tuners at one time. These were really miniature. almost the size of the TO5 can.
If I am not wrong these wre triodes for grounded grid operation.

Azzy

I think you mean a 'nuvistor', a metal can type valve, these do have low power heaters, usually about 2volts @ 0.4A, which sounds a lot, but thats only 1 watt, low for a valve heater, you'd have to use a switching reg if you want maximum efficiency from a higher voltage supply.
A 13DE7 might be the sort of thing your after, its a double triode, I dont think they are manufactured anymore but probably still available, as mentioned they were popular in TV front ends, 2 way radios and 'scopes.
This is what they look like, not made from glass, but steel.
Grounded grid operation was technique used to lower the impedance to match a 1/4 wave aerial impedance, a similar manner to a grounded base tranny, I'dve thought you'd also be able to run one in the standard grounded cathode manner just as well.

Some audio equipment just lowers the fil voltage (Cool-Tube Preamp for guitars) loss of gain but lower current.

And first of all a longer life expectancy.