There is a lot of talk around CW within the Australian SOTA community of late. I have never been a fan of morse code, but now with SOTA, it does seem like an interesting step towards a minimalistic SOTA station. Not having a morse paddle or a key that would stand up to being thrown in the backpack, I had a go at making one.
The paddles are made from printed circuit board. The block that the paddles are mounted to is made from teflon (I happen to have a lot of teflon). The teflon mounting block is bolted to the lid of a small plastic project case. Some slots have been cut in the main body of the project case for the ends of the paddles.
Contacts from the paddles are simply lengths of brass 3mm threaded rod. Pointed ends for the contacts were formed on the bench grinder. The centre contact is a just a plated hex standoff from Jaycar. Thats about it really, pretty simple. It works…. how well? I guess we will see.
One of the weaknesses of this key is the rigidity. If you push the paddles hard, they will actually bend the centre contact stand off which will then hit the other paddle and cause some extra dits or dahs.
The whole innards were taken out of the plastic box and then mounted on a piece of aluminium plate that is 5 mm thick. This does make the whole thing quite rigid now. The aluminium plate was cleaned up with sand paper and passivated in some caustic soda for a few minutes. It came out fairly well. It’s no oil painting, but it seems to work fine. Some knurled finger adjusters were added to the contacts to make adjustment easier. No too sure where they came from but there were a few in the junk box.