John Honniball wrote:
>
> MTPro_at_aol.com wrote:
> > So, anyone else like to expose any other collecting
>
> Well, I have the usual (!) collection of old electronic test gear, plus
> phones, audio and video gear:
>
> http://www.gifford.co.uk/~coredump/oldsad.htm
>
John, I don't understand this description of the knife switch:
>>
A porcelain knife switch, used for disconnecting an aerial from a radio receiver. The two centre terminals of the switch are connected to the radio and the two left-hand terminals go to the antenna. Finally, the two terminals on the right are earthed. The switch incorporates two spark-gaps which are intended to prevent lightning from damaging the radio. But the real protective measure is to switch the handle over to the earthed position whenever the radio is not in use. This connects the aerial directly to earth, and disconnects it from the radio.
<<
It seems to me that the radio is connected to earth instead of the aerial...
Bert
Received on Sat Apr 17 2004 - 07:23:35 BST