5Y3

Champ type.) It is virtually identical, electrically, to the 4-pin type 80 tube, but with an octal base.

The success of the 80 and 5Y3 led to the development of many similar rectifier tubes of both higher and lower power ratings, including the 5V3, 5W3, 5X3, 5Z3, 5U4, and 5Z4. The epitome might have been the 3DG4 of the 1960s, with a full 240 milliamp capability.

Currently, a plug-in replacement is being manufactured by Sovtek in Russia, which is has very similar specifications, but is indirectly-heated, and can support currents up to 144 mA, versus the 120 mA of the original. However the Sovtek 5Y3 is not a true 5Y3. It drops less voltage than vintage 5Y3's, and may cause voltages to run too high.

References

* [http://www.nj7p.org/Tube4.php?tube=5Y3GT] - 5Y3 datasheet from the RCA RC-29 Receiving Tubes Manual (NJ7P Tube Database)