THE GREAT MULLARD MAGIC BLOG
THE GENERAL POST OFFICE (GPO) VT VALVE NUMBERIN...
Confusing or what, the GPO had their own Valve - Thermionic numbering system comprising of a sequence of numbers in range from VT17 to VT207. Although this alphanumeric code followed the...
THE GENERAL POST OFFICE (GPO) VT VALVE NUMBERIN...
Confusing or what, the GPO had their own Valve - Thermionic numbering system comprising of a sequence of numbers in range from VT17 to VT207. Although this alphanumeric code followed the...