CR - 3/16 - An indicator that the television was on

[LorieR]

Question: What was a 'test pattern'?

Hearing test
School survey
An indicator that the television was on
Atom bomb study

Lorie

 

[Tantor]

Thansk Lorie!!

 

[eller]

Thank you!

Lori

 

[dizneenut]

Thanks!