Originally Posted by
skree
a switching regulator would not cause heat problems, and they don't interfere with cheap chinese radio so I would be very disappointed if they interfered with a Spektrum.
Got to say I agree with you on the using NiMHs though, people see the mods we used to to back in the day with AM/FM radios and think "boy, that's a good idea" not knowing enough to know that the old radios really benefitted from such a mod, whereas it's counterproductive in all modern 2.4ghz TXs as most run on a combination of 5 and 3.3v, which has to be got by regulation. Because radio manufacturers are cheap, the regulators in such radios are invariably cheap linear items - rather than the vastly superior, but slightly more expensive switching regulators - which struggle with no heatsinks and in a sealed case to dissipate the unwanted energy even with alkalines and fully charged NiMHs, never mind a lipo. This is probably not so much of an issue with the 4 cell radios but 4 cell makes it even more unnecessary to run a lipo.
LiFe is a good idea due to its lower voltages, but LiFe's power:weight/bulk ratio is quite poor. There's just no need for a Li of any kind.
I’ve always wondered about the higher voltage providing more range with a 2.4GHz transmitter. I don’t know for sure about the 4 cell jobs like a DX3R, but I do know the 8 cell DX series use a regulator. And since they are all based on chips, I suspect, but again don’t know for sure, they all are regulated to standard chip voltages as you mention. Really doubt if they are using custom chips, it’s not like 2.4GHz components weren’t already readily available.
Which would seem to preclude any possible range increase from a higher voltage battery much past 5 volts, perhaps 5 plus any associated regulator drop out.
If so this can fairly easily be accomplished in a DX3R by adding a 5th nimh battery, as there are 2 additional spots under the cover past the standard 4 spots. Or 4 AA lithiums with no mods as some do. With little risk of killing the batts (nimh only obviously) by accidentally leaving the radio on, or having a lipo puff damage the radio.