Paddle Key

My Home-brew Paddle Key - 2016 Winning entry of  the G2BQY Memorial Constructors Cup of the Trowbridge & District Amateur Radio Club

The source of inspiration for this key was a picture I had seen in a RadCom of a Kent twin paddle morse key. I already had a good collection of brass bar and other bits and pieces including a square sample of granite kitchen worktop; I thought I would save myself around £150 and make one.  

The base was from a kitchen company that was closing in Warminster, who kindly gave me several marble and granite samples.  The wood for the finger plates was yew wood, scrounged from a cabinet maker friend who had managed to obtain some of the wood from the felled  tree that  once stood outside the Westbury Post Office, now the Garden Hotel. I felt this connection with the Old Post Office and a telegraph key was very appropriate. The bearings were removed from the reader arms of two old computer hard drives. All work was done using basic hand tools, an electric drill and a small vice. The hardest part was drilling holes in the granite block and getting the holes in the brass for the bearings straight and vertical.

The accompanying electronic keyer is a simple circuit comprising 3 ICs  and a transistor.  As there was room in the enclosure, I decided to include a active CW filter.  Both circuits were taken from old Practical Wireless articles. The active audio filter uses a LM567 Phase Locked Loop and a 741 IC plus one transistor.

The CW signal from the transceiver or receiver is locked onto by the phase locked loop by adjusting the main tuning. This in tern activates the tone generator. This new combined tone is adjusted to give emphasis from one or the other depending on the required working conditions. The mix adjustment can be set for full Clone emphasis, or a mix of both.  Setting the mixture control for both, will allow you to monitor the chosen station and the Clone for your preferred pitch and level, or set for the option to hear only the clean Cloned CW.

Giving it a test drive