[BC] unreliable old equipment query

[Donna Halper]

I am posting this message to several lists, in hopes of getting some 
information.  My Canadian friend Art, who is writing a book with a 
backdrop in late 1940s or early 1950s broadcasting, asked this of me, 
and since technology is not my strong suit, I thought I'd ask you nice 
folks.  I'll pass along your replies to him.  He was reading some old 
articles about technical failures in TV equipment:  "Everyone who was 
working in TV at the time recalls how temperamental and unreliable the 
electronics were, but exactly how temperamental and unreliable is not 
spelled out.  So I am trying to find comprehensive and detailed 
information about the extent of it:  what were the most common component 
failures that would lead to loss of service (not necessarily loss of the 
signal altogether, which was quite rare.)  Essentially anything that led 
to the "We Are Experiencing Technical Difficulties" slide appearing fits 
the definition, with the exception of component failure from external 
causes:  a burst water main that shorted out the electronics, or a 
lightning bolt that fried the transmitter don't count.  What were the 
most common components to fail, how long on average would it take to fix 
them, and what percentage of the broadcast hours would the average 
station expect to lose over the course of a month?"  Any guidance you 
can offer will be appreciated!