1Ж29Б-В1j29b-v

Also known as 1ZH29b-v, 1sh29b-v and properly 1Ж29Б-В

There is also 1j29b (1Ж29Б) and 1j29-r (1Ж29Б-Р)

Useful information on these kinds of sub-miniature Rod Pentode tubes (valves):

Russian Subminiature Tubes

The 1j29b (all versions) is  still (2011) readily available to purchase as New Old Stock (NOS).

Nützliche Informationen über diese Art von Sub-Miniatur-Rod Pentode Röhren:

Russian Subminiature Tubes

Die 1j29b (alle Versionen) ist immer noch (2011) leicht zugänglich zu kaufen (2011) leicht zugänglich wie Neu Alte Aktien Kauf (NOS)

The cyrillic suffix -B (v in latin/english) indicates longer life / more durable

The cyrillic suffix -Р (r in latin/english) indicates longest life / most durable / most reliable.

The 1j29b-v (aka 1sh29b-v and properly 1Ж29Б-В) seems physically identical to the normal 1j29b (1Ж29Б) .   The 1j29-r (1Ж29Б-Р) is a different pin / wiring connection.