Edward Sandle on Navigation
This is one of the Morse keys from the old Radio Station and the more modern ones didn’t look quite the same although they worked the same way.
Basically it’s a piece of metal between two contacts and when you push it one way it breaks the contact and then when you let it go again it makes the contact.
So the purpose of the lower contact is to actually send signals to the transmitter which are then transmitted and the upper contact stops your signal going into the receiver so you don’t blow the aerial up.
The aerial was connected to the same frequency so if you do that you stop the aerial, you close the aerials and the receiver doesn’t receive, so it works on how long … you’ve got dots and dashes, a dot is quick and then the dash, you hold it longer. It’s a very basic thing.
In fact you could do it with a piece of wire, I’ve seen people doing it with a saw blade using that as a Morse key. These were overtaken by what they called side keys which operated in a similar sort of way, but they moved from side to side instead of up and down and you could send a lot faster with them.