MorseKOB Turnkey Interface
The Turnkey Interface (TKI) is just what it says - it comes fully assembled and tested ready to connect your telegraph loop into your computer. It's available for both USB and RS-232 computer ports and the USB version is now available in an oak replica WU junction box.
You will need to supply the telegraph equipment (usually a key and sounder) as well as a loop power supply. The TKI is just an interface to the computer - it basically acts as a switch and will NOT power your telegraph equipment.
A NOTE on Loop Supplies: There have been reports of unexpected operation when using a PC and DC power distribution bus, such as those commonly found in amateur radio set-ups. Apparently, an unintended ground loop through the PC can be set up that bypasses the negative lead out of the interface back to the distribution bus. Any current limiting resistors must be placed on the POSITIVE side of the interface to avoid a ground loop shorting out resistors that are placed in the Negative or Return line of the Interface/Power Supply. This allows full loop voltage and HIGH current to flow through the sounder. The best place for current limiting resistors is on the positive side of the supply as it feeds the key/sounder (see the Connection Diagram). This will protect the sounder from high current due to ground loops with the PC and power distribution busses. This is not a concern if you have an isolated supply/battery (one that is not connected to anything but the telegraph loop), but it is still good practice to current limit the positive path of the supply as it feeds the sounder.
Depending upon demand and inventory at the time you order, it could take a few weeks to build, test, and ship a unit. I am trying to keep a few completed units in stock so that I can get them out when ordered. Bare PCBs will be for sale if available, please check the availabiity - PCB pricing details on order page.