These were used in some old Ampex preamps. They’re pretty cool.
Nuvistor (http://www.thevalvepage.com/valvetek/Nuvistor/nuvistor.htm)
Also see;
http://semiconductormuseum.com/OralHistory/RCA/Mendelson/Mendelson_Index.htm
http://www.logwell.com/tech/components/nuvistors.html
http://hhscott.com/cc/nuvistors.htm
You also find Nuvistors in lots of old Tek scopes. :D
A word of caution for anybody experimenting with Nuvistors.... they love to oscillate.... at VHF frequencies! :shock: Good layout is EVERYTHING. :D
Take care,
-Peter
Thank's Mr Hugh, I just found some in a box of stuff I was rummage'in through and I wondered, What in the heck are these little guy's, now I know :idea:
JD