tesla: Voltage dropping resistor value

I have a 305U with the later round IF cans.  Every picture I am seeing has a cutout at each side of the dial for two dial lamps.  Mine has one cutout and one dial lamp.  The reason I am going into detail is the bottom half of the tall dropping resisot is open.  The schematic shows this section to be 200 ohms for 2 dial lamps.  Do I have an earlier version and if so, what will the value of the bottom half of this resistor be?  Also, the top half measures 900 ohms. This would seem to be more in keeping with one bulb.

Best regards,

Donald Cochrane

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Hi Don,

In 120 volt position, you have a 200 ohm resistor plus 3 tubes plus the bulb in serious connection. This results to 120 volt. In a second string you have a 700 ohm resistor plus the rectifier tube. This results to 120 volt too. Current in both strings is 0.1 amp.

If you measure 900 ohm, this is the sum of both resistors. There must be a center tapping where you should measure the 200 ohm to one side and 700 ohm to the other side.

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Thank you for your very kind reply.  I measured from the center tap to the top, 900 ohms.  The bottom is completly open.  I have also found out, this appears to be the earlier 304U.

Best regards,

Donald

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Hi Don,

If the lower resistor is missing, only the rectifier tube is heated and the other 3 tubes and the bulb are not heated, right?

Rolf

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