Televisual Holy Grails

[Markymark]

I don't know if this counts as a holy grail, but I remember in the 1980s, if the BBC had to put out a transmitter information announcement, they had this slide, with "TRANSMITTER INFORMATION" in bold black lettering, with a black transmitter on the left, on a gloomy blue sky background. For a while, STV had their own one, with the IBA logo, and "TRANSMITTER INFORMATION" below it, all in red on a black background. Never seen these slides on web searches.

The Beeb sometimes used to just use a picture of someone's domestic aerial 

30 secs into this
https://youtu.be/hc--azOhY4w