01-23-2014, 01:15 PM
Kirk
Once the L49B is numbered right according to the L49B actual data (I gave you the link), look at the diagram.
What L49B is is a ballast tube: it drops some voltage at a given current (in short it is simply a glorified resistor) so the rest could be applied to the serialized filaments of the other tubes, and at the same time uses a tap in that resistor to derive the voltage to power the dial lamp(s).
Now I believe it has just 3 pins that are functional - the beginning, the tap and the end of that resistor. The rest of the pins is typically a dummy - the pins do not go anywhere or even missing.
Now once you have mapped your socket with correct pins and look at the tube's data, look how the MAINs wires actually connect. One, very similar to the Stromberg radio diagram I listed, will go directly to the beginning pin of the ballast.
The other then should go to a pin that is dummy or not used, they usually do that to use a spare pin as a solder post, for convenience. If it is the case (and I think it is) you are OK.
PS. A diode is not a resistor, cap or whatever, It is a semiconductor with a P-N junction which by its nature works as a one-way conductor for DC. Consider it two pieces of separate metals (or rather semiconductor materials) touching each other. The rest is physics and it is complex - you would have to learn about bandgaps, Fermi levels and all the good stuff which you do not really need.
Important is: a Si diode (silicon) will conduct current one way, not conduct the other and when conducting will drop about 0.7V across itself. This is it.
Once the L49B is numbered right according to the L49B actual data (I gave you the link), look at the diagram.
What L49B is is a ballast tube: it drops some voltage at a given current (in short it is simply a glorified resistor) so the rest could be applied to the serialized filaments of the other tubes, and at the same time uses a tap in that resistor to derive the voltage to power the dial lamp(s).
Now I believe it has just 3 pins that are functional - the beginning, the tap and the end of that resistor. The rest of the pins is typically a dummy - the pins do not go anywhere or even missing.
Now once you have mapped your socket with correct pins and look at the tube's data, look how the MAINs wires actually connect. One, very similar to the Stromberg radio diagram I listed, will go directly to the beginning pin of the ballast.
The other then should go to a pin that is dummy or not used, they usually do that to use a spare pin as a solder post, for convenience. If it is the case (and I think it is) you are OK.
PS. A diode is not a resistor, cap or whatever, It is a semiconductor with a P-N junction which by its nature works as a one-way conductor for DC. Consider it two pieces of separate metals (or rather semiconductor materials) touching each other. The rest is physics and it is complex - you would have to learn about bandgaps, Fermi levels and all the good stuff which you do not really need.
Important is: a Si diode (silicon) will conduct current one way, not conduct the other and when conducting will drop about 0.7V across itself. This is it.