[GreenKeys] Thyratron used in audio ! !

[Bruce Gentry]

The type 884 triode thyratron was very popular as a sweep generator in 
ultra low budget oscilloscope kits. Many kids bought and built them with 
"cut grass-pump gas-throw newspapers" money.  If the 884 tube failed, it 
was so expensive to replace that the scope would often be scrapped or 
re-purposed as a tuning indicator for an RTTY modem.  I bought one of 
the scopes, missing the 884, at a flea market (in 1967) for 75 cents and 
used it for that exact purpose. Who remembers or built a modem using 
television horizontal oscillator coils for the filters?    AND- I do 
remember the "cry baby" signal in old telephone switching systems.

      Bruce Gentry KA2IVY

On 3/22/17 7:49 PM, Larry Tighe wrote:
> *Western Electric used the 297A thyratron for audio! !  It was used in 
> the C.O. switch.*
> *Panel and Stepper offices used a "cry baby" when a customer hit any 
> digit with the*
> *rotary dial that was not allowed. Such a digit landing upon a vacant 
> selector position,*
> *for example, would route that customer immediately to the cry baby.  
> It would be the*
> *297A connected to an R C network that keyed on a one second pulsing 
> relay to ground.*
> *Only old people will remember the cry baby   weeeee oooooh weeeee 
> ooooooh.*
>
>
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