I was going to change the dial lite on a Sparton 601-B radio, that I'm working on , the schmetics give a Sparton part number only (A-14924) , the old lite is a #51 , I know they are VERY critical in using the correct amp draw lamp ! The rectifier tube is a 35Z5 in this set, is this the correct lamp or has somebody changed it out, with the wrong lamp ?
Thanks, Lee , Joliet, IL.

Datasheet has rules of using shunt resistor in the case of .15 amp lamp such a no. 47 where plate current is greater the .060 amp. A 51 lamp (.02 amp) may have been used instead if this radio's plate is higher than .60 amp which doesn't seem likely. Would need to insert a milliamp meter in the plate of the 35Z5 to be sure. Richard

http://scottbecker.net/tube/sheets/093/3/35Z5GT.pdf

http://www.nostalgiaair.org/References/lamps/

:Thanks for your help ,Richard ! I will check that plate current of my 35Z5 tube, my friend also thought a #47 would probably be a better replacement (original type) lamp ! The insulating paper around the dial lite socket, made it impossible to remove the #51 lamp (with the globe glass) , the #47 appears to be a better "fit" ! Lee
:Datasheet has rules of using shunt resistor in the case of .15 amp lamp such a no. 47 where plate current is greater the .060 amp. A 51 lamp (.02 amp) may have been used instead if this radio's plate is higher than .60 amp which doesn't seem likely. Would need to insert a milliamp meter in the plate of the 35Z5 to be sure. Richard
:
:http://scottbecker.net/tube/sheets/093/3/35Z5GT.pdf
:
:http://www.nostalgiaair.org/References/lamps/
:

::Thanks for your help ,Richard ! I will check that plate current of my 35Z5 tube, my friend also thought a #47 would probably be a better replacement (original type) lamp ! The insulating paper around the dial lite socket, made it impossible to remove the #51 lamp (with the globe glass) , the #47 appears to be a better "fit" ! Lee
::Datasheet has rules of using shunt resistor in the case of .15 amp lamp such a no. 47 where plate current is greater the .060 amp. A 51 lamp (.02 amp) may have been used instead if this radio's plate is higher than .60 amp which doesn't seem likely. Would need to insert a milliamp meter in the plate of the 35Z5 to be sure. Richard

The type 51 bulb was intended for instrument lights on 6 Volt cars. A 47 was probably what the maker intended to go there.
Lewis

::
::http://scottbecker.net/tube/sheets/093/3/35Z5GT.pdf
::
::http://www.nostalgiaair.org/References/lamps/
::
:

:::Thanks for your help ,Richard ! I will check that plate current of my 35Z5 tube, my friend also thought a #47 would probably be a better replacement (original type) lamp ! The insulating paper around the dial lite socket, made it impossible to remove the #51 lamp (with the globe glass) , the #47 appears to be a better "fit" ! Lee
:::Datasheet has rules of using shunt resistor in the case of .15 amp lamp such a no. 47 where plate current is greater the .060 amp. A 51 lamp (.02 amp) may have been used instead if this radio's plate is higher than .60 amp which doesn't seem likely. Would need to insert a milliamp meter in the plate of the 35Z5 to be sure. Richard
:
:
:
:
:The type 51 bulb was intended for instrument lights on 6 Volt cars. A 47 was probably what the maker intended to go there.
:Lewis
:
:
:A special thanks to both Richard & Lewis for your help ! I checked this morning , with the #47 dial light installed and a 200 watt light bulb in series with the radio ( for safety) , I've got about .044 amp draw on the plate of the 35Z5 tube, looks like a perfect candidate for the #47 dial light application ! Lee
:::
:::http://scottbecker.net/tube/sheets/093/3/35Z5GT.pdf
:::
:::http://www.nostalgiaair.org/References/lamps/
:::
::
: