What does NBS-4 stand for?

NBS-4 stands for "Older Primary Frequency Standard"

How to abbreviate "Older Primary Frequency Standard"?

"Older Primary Frequency Standard" can be abbreviated as NBS-4

What is the meaning of NBS-4 abbreviation?

The meaning of NBS-4 abbreviation is "Older Primary Frequency Standard"

What does NBS-4 mean?

NBS-4 as abbreviation means "Older Primary Frequency Standard"