New Spektrum DX3r Observations

[BrianG]

I don't know. Considering actual RF output is measured in milli-watts, the battery voltage probably doesn't affect range (Spektrum has confirmed this). So, the gains must be in the display and/or circuit topology. Maybe the new radio has more of the circuit integrated onto one IC, which can save power over discrete components. I've only had it a very short time, so I don't have any data about the "runtime".

[jhautz]

Originally Posted by abiye

if you lower the frame rate setting to 5.5ms you'll notice the speed difference... you need to have digital servos howerver... i'm running ace 1015 servos in my losi 8's... also i'm using lipo rx pack without a regulator... at 6v they're rated at .10, at 8.4, silly fast... with the 5.5ms setting you can't even see the wheel... lol

I am running digital servos and the 5.5 frame rate... Still cant tell a difference. The faster frame rate doesn't make the servos move faster, it just reduces the latency from when you turn the wheel to when the servo starts to move. When these things start getting measured in mili-seconds its beyond my mortal abilities to tell the difference. I'm sure there is probably sombody who can...but not me.

[jhautz]

Originally Posted by BrianG

I don't know. Considering actual RF output is measured in milli-watts, the battery voltage probably doesn't affect range (Spektrum has confirmed this). So, the gains must be in the display and/or circuit topology. Maybe the new radio has more of the circuit integrated onto one IC, which can save power over discrete components. I've only had it a very short time, so I don't have any data about the "runtime".

The way I understand it is the older FM style radios were based on older tecnology and needed more power for pushing the FM or AM based signals. The original radios were still designed around that same technology and then just retrofitted to use the 2.4ghz. The 2.4ghz wanvelength is shorter so it travels farther on less power. Designing the entire radio around this allowed them to use less battery power to brodcast the signal.

BTW. I have noticed no range loss on batterys that were just about to die. It has a low voltage alarme you can set. I have mine set to start beeping at 4.1v and it seems to still have the same range as with freash batteries. I havent pushed it to find out exactly what voltage it stops working at though.

I can sure tell you that comparing this thing to my old M11 made the M11 feel like holding a brick. At first it felt wierd that it was so light, but now that Im used to it I picked up a buddys M11 and I couldnt believe how heavy it felt.

[lincpimp]

Originally Posted by jhautz

The way I understand it is the older FM style radios were based on older tecnology and needed more power for pushing the FM or AM based signals. The original radios were still designed around that same technology and then just retrofitted to use the 2.4ghz. The 2.4ghz wanvelength is shorter so it travels farther on less power. Designing the entire radio around this allowed them to use less battery power to brodcast the signal.

BTW. I have noticed no range loss on batterys that were just about to die. It has a low voltage alarme you can set. I have mine set to start beeping at 4.1v and it seems to still have the same range as with freash batteries. I havent pushed it to find out exactly what voltage it stops working at though.

I can sure tell you that comparing this thing to my old M11 made the M11 feel like holding a brick. At first it felt wierd that it was so light, but now that Im used to it I picked up a buddys M11 and I couldnt believe how heavy it felt.

I just picked up an M11 and a pair of m8s. I like the feel and features of the m11, much better than my futaba 2pl and 3pm. I have a spectrum module and a couple of novak switches, and a bunch of novak synth receivers. I plan on running mainly fm, but will run spectrum on my top speed project. I have had great success with fm, did notice that my 3pm had much better range than my 2pl. I have not had much time to test the m11 yet, off the bench. It is really easy to set, even mixing channels and setting all of theother cool functions! Had to glance at the manual a few times...

I can see the benifit of 2.4 when racing, no need to lug around a bunch of crystals! I would buy a new radio, but I have only spent about 600 bucks on the 3 radios and about 20 receivers...

[jhautz]

I hear ya linc. nothing wrong with good old FM, still works great. I just prefer the security that I know nobody else is gonna flip on their radio and my RC is gonna run amok. (I think thats how its spelled.)

i've had mine for a few months and i can say that its the most efficient radio i've has when it comes to power consumption... i've had airtronics mx-3, jr xs3 and futaba 3pk with spectrum module...

[MetalMan]

Brian, here's an idea for you - if you could fit a 2s Lipo in the battery tray, grab a 5v switching regulator and hook it up to the 2s Lipo with a switch between the two, and plug the regulator into the DX3R's battery input. You could also throw a low-voltage buzzer alarm onto the switching regulator's input that is set off at 6+V. Then you can have a Lipo-powered DX3R that won't receive too high of voltage due to the switching regulator, with huge runtime compared to the batteries you have in there right now, and no chance of over-discharge (assuming you don't accidentally leave the regulator on and cannot hear the buzzer). And if you currently have rechargeable AAs, then you won't have any self-discharge to worry about!

[gixxer]

I have this radio and really like it . Its very comfortable and light. I also have one of the first released ones but haven't had the bind issue.

The only things that I wish they added are a backlight, and the ability to slow down the servo speed. I had a jr-z1 before this and that was nice but I do like the 3r better.

Also it seems to be good on batteries. I am running 4 2500mah rechargibles and dont know the exact runtime but long enough not to have to worry about it. I had a lipo in my other radio of obviously that lasted longer but it not enough of a problem for me to worry about getting a lipo and regulator.

[BrianG]

Jhautz: I was thinking new Spektrum vs old older Spektrum, not other radios. That makes sense, older technology is almost always less efficient than newer.

The size and weight is certainly a lot less than the DX2/3/2.0/3.0! Not only that, but the reduced weight on top makes it less top heavy - not that the old one is bad, you just notice the difference when holding both.

The 2.4 security is nice, and it's sure easier than carrying crystals when at the races. However, the main reason I got mine is the 30 model memory.

MetalMan: I've already thought of that. I am a little hesitant because what if I do accidentally leave it on and don't hear the buzzer? I would rather have an LVC than a LVW (low voltage warning). The latter is passive protection, the former is active protection. I have a LVC circuit idea that I might try.

[MetalMan]

Originally Posted by BrianG

MetalMan: I've already thought of that. I am a little hesitant because what if I do accidentally leave it on and don't hear the buzzer? I would rather have an LVC than a LVW (low voltage warning). The latter is passive protection, the former is active protection. I have a LVC circuit idea that I might try.

I thought of it first lol. This is what I've been using in my Nomadio React for almost a year now. At one point I did accidentally leave it on before installing the low voltage alarm, and puffed a 2s 2100mah pack, but I had another. It's been fine for quite some time now, especially since after killing that first pack I also installed an external switch between the Lipo and the regulator.

[lincpimp]

Or, you could use a pair of cell phone batteries, as they have an lvc built in. You would still need a voltage regulator to get it down to the correct voltage. Sike knows more about this than I, but I have been using nokia cells (3s) in my 2pl and 3pm for a while. They are only 1000mah, but are super light, and I have a few packs made up so that I can swap them out. i have also seen some of the voltage regulators that have active lvcs built in. They are designed for lipo receiver packs in nitro vehicles, but should work as well in a radio.

I also just made a lipo pack for my M8 radio. Used 3 2500mah 18c cells that I had laying around, as they fit the strange battery tray perfectly. That radio has a 9.1v buzzer built in. It is not an active lvc, but hopefully I do not leave it on... Do you think that 18c is a bit much for a radio battery...