3B Scientific Teltron Electron Diffraction Tube S - Manual (Page 3)

3B SCIENTIFIC® PHYSICS
1
Conversion Instructions for Tube Holder S
(1000610, U185001 or U18500)
09/13 ALF
The quality of the electron beam in electron de-
flection tube S (1013889) is affected by the resis-
tance between sockets C5 (cathode) and F4
(heating filament) on the tube. For optimum re-
sults, the resistance R
C5F4
needs to be 390 kΩ.
Tube holder S (1014525) is accordingly designed
such that this resistance is present.
Older designs, sold under numbers 1000610,
U185001 and U18500, feature a much smaller
resistance. In order to operate the new S model
electron deflection tube (1013889), these old
tube holders need to be modified. The alterna-
tives are to replace the resistor on the original
board or replace the whole board with a new one.
The replacement board can be ordered under
order number 4008573 for a charge. Replace-
ment can be carried out without the need for
soldering. The tools required are as follows: 1
flat-blade screwdriver, 1 cross-head screwdriver
and 1 Allen key (2.5x112)
The following equipment is needed to replace the resistor:
1 Resistor 390 kΩ (replacement supplied with electron deflection tube S)
1 Cross-head screwdriver
1 Soldering iron
Solder
1) Turn the tube holder over and undo all the
screws. 2) Place your thumb under the guide pillar at the
bottom, using this as a fulcrum. Gently pull the
bar to lever the base out of the tube holder.