More information about these tubes:
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
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.
Each matched pair is supplied with a 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!