Boscam BOS 600 is a 5.8GHz 600mW 32 channel video transmitter well suited for long range (> 1km) FPV flights. Its design makes the whole casing a radiator. This is good, since 600mW of RF means a lot of heat. Unfortunately, Boscams BOS 600 design has a serious bug there: so what if whole casing can act as a radiator, since connection between RF module and casing is poor? Just look at picture below.
RF chip is not even touching casing, gap is filled with a blob of thermal compound. Add far from perfect quality control and you will have overheating transmitter that will loose output power or even burn. But it can be fixed with a small piece of 2mm thick thermopad.
- Open casing by removing 4 screws on the sides of transmitter
- Clean RF chip and casing from existing thermal compound
- Cut a pice of thermopad similar in size to metal block screwed to bottom part of casing
- Remove protective film from thermopad and put it in metal block
- Assemble whole unit and screw both parts together. Thermopad will tightly fit the gap between RF chip and casing, making heat transfer easier
- As a final touch I have added an additional aluminium radiator that I’ve bought for my Rasperry Pis. But this is not needed, and can be skipped
Final note of thermopads. They come in different thicknesses. 1mm and 2mm should be fine for DIY projects, and can be bought cheap from eBay or any other internet store. Strip big enough to improve dozen of BOS 600 transmitters should cost not more than few dollars or euros.