In the Radio receiver design # FM vs . AM article there is mention of an " valve holder tax " that the UK goverment imposed.
2.
The UK radio manufacturers had to pay a royalty of ? per valve holder to the British Valve Association to cover use of their members'patent rights.
3.
Although used in circuits such as tape recorder input stages and instrument amplifiers, microphony can be a problem, even when mounted in a vibration-reducing valve holder.
मोबाइल