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Vacuum Tube LEDs: Fully Dressed 21HB5A

2016-09-20

Electronics Workbench Machine Shop

Arduino, Improvements

Black PETG definitely looks better than cyan for this job:

21HB5A - Black PETG base - flash — 21HB5A – Black PETG base – flash

Holding the plate cap to the tube with a thin ring of opaque epoxy cuts down on the glare under its edge:

21HB5A - Black PETG base - cyan phase — 21HB5A – Black PETG base – cyan phase

Fire in the bottle!

21HB5A - Black PETG fittings - punched drive platter - purple phase — 21HB5A – Black PETG fittings – punched drive platter – purple phase

It’s still running basically the same Arduino code as before, but I have some ideas about that…

Comments

2 responses to “Vacuum Tube LEDs: Fully Dressed 21HB5A”

2016-09-20

madbodger

The reflection of the surprisingly regular mottling of the lower mica is unexpectedly nice.
1. 2016-09-20
  
  Ed
  
  The mica sheets in those 21HB5A tubes look like they have a powdery white coating, quite unlike the usual shiny dark-silver mica sheets in my other tubes, that lights up wonderfully well under the LEDs.
  
  Peering at the bottom of another 21HB5A, I think the mottling comes from refraction around the pins. Each pin has a glass cylinder melted around it; they may have put a sealing bead on each pin, combined those with a glass tube base, then melted that whole assembly onto the tube envelope. Plenty of forgotten tech involved in that process, fer shure!