Many types of nuvistors were produced in the Soviet Union until the begin 90's. Unlike the American types, the Russians produced them with long, flexible leads, because they did not use plugs for these tubes. In addition to triodes, tetrodes also produced pentodes in this form, even power pentodes.
Some nuvistors from Soviet Union:
Standard triodes 6C51H (7586), 6C52H (7895), 6C62H
Low voltage triode 6C63H
UHF triode 6C53H (european EC1010):
Tetrodes 6Э12H (7587), 6Э13H, 6Э14H
Small signal pentode 6Ж54Н (and triode 6C65H has identical form, differs from standard classical nuvistors)
Power pentode (Pa = 15W! grater than EL84 tube) 6П37Н
Suffix -B means military version of tube (6C51H - standard version, 6C51H-B - military version).
Some of them were like 6C51H, 6C52H, 6Э12H produced in huge numbers, still easy to buy, cheap. The rest are considered rare (small amount of production). Relatively easy to acquire is this 6П37Н power pentode.
Another very interesting tubes are the rod tube, invented in the Soviet Union and only produced there.
https://www.radiomuseum.org/forum/russia...tubes.html
Some nuvistors from Soviet Union:
Standard triodes 6C51H (7586), 6C52H (7895), 6C62H
Low voltage triode 6C63H
UHF triode 6C53H (european EC1010):
Tetrodes 6Э12H (7587), 6Э13H, 6Э14H
Small signal pentode 6Ж54Н (and triode 6C65H has identical form, differs from standard classical nuvistors)
Power pentode (Pa = 15W! grater than EL84 tube) 6П37Н
Suffix -B means military version of tube (6C51H - standard version, 6C51H-B - military version).
Some of them were like 6C51H, 6C52H, 6Э12H produced in huge numbers, still easy to buy, cheap. The rest are considered rare (small amount of production). Relatively easy to acquire is this 6П37Н power pentode.
Another very interesting tubes are the rod tube, invented in the Soviet Union and only produced there.
https://www.radiomuseum.org/forum/russia...tubes.html