06-10-2021, 05:37 PM
(06-10-2021, 12:23 PM)Mike Watterson Wrote: Joe Sousa brought this ЭМ-10 rod tube to my attention:
https://www.ebay.com/itm/322895472704
https://www.radiomuseum.org/tubes/tube_eem-10.html
About 17 mA @ 0.7V. Notice the shield at the base? It's for electrometer or other very high impedance applications. Though the 1j42a and 1j24b are good too.
I found this Electrometer schematic years ago on a NASA web site.
I too have that Nasa schematic. I also have a copy of the document that it came from, if anyone is interested. It does show four circuits, if I remember rightly. One uses the эм7 which you mention in your next post. This is a electrometer triode with 1V 18mA heater. These valves may be a little limited though, for normal purposes, as they are designed for low grid current etc and end up having very low gm. They are designed for very low voltage use though. эм7 - Anode 7V.
Tracy
