A pair of these solid state devices are drop in replacements for the C16J thyratron tubes used in the “Modular Drive” and “WIAD – Works In A Drawer” versions of the Monarch 10ee toolmaker’s lathe. If you have one of these great lathes, then you know what a problem finding and replacing the thyratron tubes can be. A pair of these SCR (silicon controlled rectifier) replacements does exactly the same job as the original tubes and better at a fraction of the cost.
With the exception of one wire which is eliminated, the replacements install and connect in the lathe in exactly the same way as the original tubes. They are also smaller, so installation is easy.
Some other advantages are:
In the lathe, a pair of replacements consumes between 155 and 400 watts less power than the original tubes depending on the load. So there is less heat generated, there are no filaments to burn out, and you can leave your drive powered without worrying that you are burning out your expensive and irreplaceable thyratron tubes.
Unlike the original tubes, the replacement gate turn on threshold is tightly controlled at about 0.8 volts and will not change appreciably over time. As a result, the replacements are closely matched device to device, and you don’t have to worry that you are getting less than optimum performance because one of your tubes is firing late, or not at all.