Octal Tube Socket Quartet Mica Filled Phosphor Bronze Pins USA Made

Description

For sale is a quartet (4 Pcs.) of Northern Technologies Mica Filled Octal Tube Sockets, with circular phosphor bronze and hot tin dipped pins. These sockets were USA made in Arkansas. You cannot compare the quality of these sockets with anything from China or Russia. Due to the use of phosphor bronze material for the pins, they retain their shape after many insertions.
As an insulator, the mica filled base is a superior material for dialetric strength. Older amps have a lot of dirt and minerals deposited on the surface of the sockets, and can be prone to arc-potentially damaging the output transformers.
Circular pins can contact the tube pin up to 300 degrees, whereas the hairpin type will just contact less the 10 percent of the contact area of the tube pin. Most of the ceramic Chinese and Russian sockets are using cheap metal for the pins and many of them are the hairpin style design.
They can be top or bottom mounted depending on the hole size. Diameter of the top hole is 1.250 Inch. From the bottom is 1.15 Inch.
Marshal and most British Amps were designed for Amphenol Octal Sockets which are of a similar size.
These sockets were custom made for Rivera Amplification and were used for the TBR Series of their amplifiers.