Submitted by Eric Daniel
Many of you have commented on the availability of upgrade and adapter parts, as well as a few in-house modifications you have done to keep your AN/SDU-5/E distress strobes working and I figured it was time to create a separate entry for that venerable, but definitely still functional, pocket strobe light.
For the uninitiated, the AN/SDU-5/E is a personal distress strobe light originally carried by aviators as a piece of their survival kit. The strobe light was originally designed to run off of one BA-1574/U mercury battery (NSN 6230-00-067-5209.) These batteries have been rendered obsolete and have since been replaced by a number of alternatives, including the BA-5374/U lithium manganese dioxide battery (NSN 6135-01-455-9846) as well as the Kodak 123 lithium camera battery (in the case of the 123 battery two are required, as is an adapter for the battery well.)
The SDU-5/E can also be equipped with a flash guard/Blue Filter FG1C NSN 6230-00-401-2285. The purpose of this filter is to change the color of the strobe flash from white to blue. The filter also channels the strobe, making the beam steer-able, rather than omni-directional. When not in use, the blue filter can be stowed over the body of the SDU-5/E.
The second filter the SDU-5/E uses is an IR cap. The IR cap completely covers the strobe light, rendering the pulse invisible to the naked eye. Night vision devices, however, can readily see the pulse. Both filters cannot be used simultaneously. When not in use, the IR cap is stored over the SDU-5/E light.