Original #27 tubes (227, 327) in globe/pear style bulb shape from late 1920s to early 30s. The 27 was introduced in 1927 in this glass style and was one of the first indirectly heated cathodes. The DeForest 27 is a bit rare.
Original #27 tubes (227, 327) in globe/pear style bulb shape from late 1920s to early 30s. The 27 was introduced in 1927 in this glass style and was one of the first indirectly heated cathodes. The DeForest 27 is a bit rare.