I have, finally, got onto the 2.4 GHz bandwagon. I have been reading a lot about the heat issues, etc. I would like to record my experiments and results on this.
To start with, the receivers I got with my Tx were (all) R 6014FS with a white dot. I asked around and got a "non dotted" Rx (6014FS) and conducted this experiment.
The Rxs were placed in my car with them being directly exposed to the sun, with the windows up. I have a room thermometer whose scale goes uptil 55 degrees Celsius. The end stop is perhaps a few degrees further on. After a minimum of an hour with the thermometer going right off scale, (indicating at least 60 degrees) the receivers worked fine. Binding was immediate without ANY problems, whatsoever. The RXs were fairly warm to the touch.
Yet, I have, personally observed problems with earlier Futaba sets. I can, with my very limited research, only conclude that:
The issues, if heat related, affected only some Rx. Or it was something else.
Maybe someone just went dottie!
What is the dot thing about?
Supposedly, the early receivers had some issues. Futaba - again supposedly - released versions with a dot between the antennae. Again, according to the grapevine, these were re-tested, improved or whatever.
No one knows for sure.
Here is a video that shows the problem, on a receiver exposed to direct heat.
http://www.youtube.com/watch?v=d_rsPyexRiA
http://www.youtube.com/watch?v=f3c5n7bMYoY
The issue is real, but a non-issue with basic precautions. I would urge you the same, if you have an older batch RX.
And this post has a video of testing one of the newer RXes.
http://www.rcindia.org/radios-and-receivers/are-you-still-skeptical-about-2-4ghz-radio-systems/msg10444/#msg10444
Quite possibly. But what I was trying to get at is that it appears that not ALL of the older sets had problems. The one I borrowed worked flawlessly at 60 degrees plus. No different from the "white dot" one.
One way to look at this is to see if the problem chip was changed, or did they do any kind of heat-sink type of solution on it. This would require opening up the receivers though.
The chip is mentioned here (ML2724) :
http://www.rcindia.org/radios-and-receivers/are-you-still-skeptical-about-2-4ghz-radio-systems/msg7765/#msg7765