"Sam Goldwasser" wrote in message
...

Hmmmm. Cost of electricity to run heaters: Totally rough guess of 100 W
over
10 years or about 8,000 kW-h. What did electricity cost back then?

About 3 cents per KWh.

How did the cost of the electricity to keep the heaters lit continuously
compare to the cost of a service call to replace a tube?

I'd have been doing the replacing and the kine ran till the set died. They
didn't all do that, for sure, I replaced my share for other people. That's
how the old tube computers kept going too, keep the filaments alive.
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