Here another update from the tube factory. Last month was busy with some renovation of the work places ongoing. Now tube production is in full swing.
Above the new packaging for the 300B tubes which just arrived. The packaging reflects the change on the company while it retains the Elrog as brand name for the tubes.
There are also some changes made to the tubes themselves. We are now using new bases which are custom made for us by Reinhöfer Electronic:
These are beautifully made with massive pins which provide more stability. We also did some changes to the glass bulbs. While in the past the top of the glass was shaped in house by hand, we now get these done by a professional glass blower for laboratory glass ware:
While the glass itself remains the same special glass made in Germany by Schott, we now deliver the raw glass tubes to Schmidt Laborglasgeräte where they receive the final shape. This gives a more uniform look from tube to tube. However for those who prefer the traditional hand made look, we are still also doing these. With these changes each part of the tubes and each manufacturing step is entirely done in Germany.
Here a peek into the factory floor, showing the vacuum pump stands:
Assembled 300B tubes waiting to be put on the vacuum pump:
The tubes on the pump:
I am planning a series of posts 'Making of a vacuum tube' which will show each step in detail. Here a brief preview what will be shown in upcoming posts:
Here we see Olena preparing filament assemblies for 300Bs. Also captured on video:
Tiny 50 micron thick thoriated tungsten wire:
Which gets spot welded into the filament assembly frame:
Here we see a close up of an assembled 300B on the vacuum pump ready to get outgassed:
Each plate carries the initials of the person who assembled it. In this case it was made by Olena. The internals get heated up by RF induction through the coil. This drives gasses out. During the entire process the tube is exhausted:
The plate glows bright red during this step.
The surface of the plate turns to the characteristic grey :
I hope you enjoyed this glimpse into the tube factory. Stay tuned for more detailed posts about the making of a vacuum tube!
Here we see a matched pair in it's packaging with the measurement protocol. Each pair gets selected to within less than one mA in two op points. We now typically reach extremely low grid currents in the range 30-40 nano Ampere!
Inquiries about the Elrog tubes have been tremendous. November production is already pre ordered. If you are interested in 300B, 211 or 845 tubes, please pre order soon since we expect December production to be sold out quite quickly as well.
Here a quote from a customer who received his ER300B tubes recently: