Hi, I've found that a 'waist pouch' works great at night, and don't have problems with weak signal. I use the kind designed for passports, very lightweight, that can be under clothing while traveling. My MM transmitter is over 3 years old. With the waist pouch, I can keep it 'in the middle', and within range of the sensor, usually on my thigh.
I get weak signals from time to time, but they always resolve on their own. The transmitter will store 45 min of data, so there should be no gaps in the data. Unless it has been a long time and then you should get lost sensor. I suggest that you push in the transmitter hard, even more after the click.
I noticed that At the gym, the heart monitors in the treadmills will interfere with the pump receiving the data. When ever I'm near one it stops communication. It comes back when I am a few feet away. Maybe you have something near your bed, like a wireless phone transmitter or cell phone too close to your bed.
The battery only lasts about a year in the transmitter, so if you are out of warrantee, You prob do need a new one.
I used to have a Dexcom 7 and that one did not have a rechargeable battery. IT just went when it went. I got missing data all the time and even the clockradio would interfere.
I did find a way to use my Dexcom sensors with my MM pump, I had 7 sensors left and and a exengineer for DEXCOM told me how to do it. I wont share that here as he asked me to not EVER tell anyone. I think the dexcom sensors are better, but the MM system is superior in transmission and collection of data. Besides they don't sell you Dexcom transmitters unless you own a Dexcom system. It only would help those who have sensors left over.
I'm thinking that Minimed should just allow us to use Dex sensors. I think people would be more likely to buy a MM pump if it was more versatile. Everyone wants to have propritary stuff these days, but i think they would sell more if they opened up the system.
Anyway the communication technology is exactly the same in the two systems. I don't know why one would work differently, unless the the transmitters on the dex are better, but the power on the dex is lower, so I would think it would be less effective.