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Old 05-06-2014, 06:44 PM
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bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,808
TS-4 through TS-4H chassis use the 17A470303 ballast.
TS-4J and TS-18 chassis use the 17A485459 ballast.

It doesn't matter if it's metal or glass - the part # is the same.

For a brief time there was a supply of NOS glass 17A485459 ballasts at $15 a pop. That dried up a couple years ago. $65 may sound high, but they rarely show up for sale.

The glass ballasts use iron wire in hydrogen gas which provides a regulation effect to suppress the surge current on start up. That's easy enough to replicate with the use of a modern thermistor like the CL-90.
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