- You are lucky with your personal experience with the MH-8A. But we have a much broader experience with many many divers. We have sold the Hollis models which used the MH-8A's and of course sell the Shearwater models which support the MH-8A as well. We've sold literally well over 1,000 of the the MH-8A. We had many complaints regarding the loss of signal I mentioned earlier. Initially we recommended that if a buddy pair both had a transmitter, then use two different colors (we only ever saw the gray and yellow) although we were often out of stock on the yellow. It didn't seem to make much difference and it was later discovered PPS had been shipping the yellow with the same timing as the gray! The yellows were updated and in many cases that helped with the issue. Regardless MH-8A were a constant headache... for whatever reason there seem to be subtle compatibility issues between specific units of the transmitter and specific units of the dive computers. We found we could sometimes just exchange either a transmitter or a computer and the issue would get better or disappear. Interestingly, we had some customers that nothing we tried significantly improved the signal loss problem regardless of what we did... I have a theory that some customers perhaps have a very small electrical field on or near their body while in saltwater such as galvanic current from a specific orientation of dissimilar metals in their equipment or from lights, maybe a plate in their head or a pacemaker... never figured it out. Often putting the transmitter on a short HP hose would improve the situation. Conversely we also had some customers with two transmitters of the same color and so did their buddy, and for them there was never ever an issue, rock solid. As for the "latest" firmware recommendation, I was told there were some (unsuccessful) attempts to address some the issues using tactics in the dive computer firmware... but not knowing what version the diver has, it's prudent to recommend they always start with the current versions when diagnosing an issue.