Camera buffs can purchase inexpensive versions of remote triggers for external flash units, controlling either hot-shoe or 'studio' type flash units. These triggers suffer from low transmitter power and thus small effective control distance.
This mod adds a correctly sized antenna, effectively increasing applied power and thus allowing operation from much greater distances. I have seen increases of tenfold in control distances after this mod.
This mod will show how to open the transmitter (RF-04/RF604), create the antenna wire, locate the place to attach the antenna, mod the case, and the final construction. Enjoy.
Note: this instructable was derived from material presented in the Strobist blog, here
, with the actual article here
. The original description is here
I found this model on ebay, from a great supplier: Magic_Trigger
. There are others on ebay and other locations, but I can't speak to the exact design they use or how to modify them, but similar techniques can be used.