2.4 GHz Receiver Question (how many?)
 

Step away from this hobby for a bit (well... 8 or 10 years or so), and it feels like I'm starting over, technology wise...

The new 2.4GHz technology is very impressive and a bit overwhelming.... really enjoying the process of getting up to speed.

My question is pretty simple. I have been searching and I am not finding the "opinion" I'm looking for... one of those questions that will vary with the user... but, it is important to me to get those varied inputs.

In short, how many receivers and how many remotes for varying aircraft types??

In my little .60 size fun plane, this is not a difficult question. In my 120cc gas Edge, this will be easy as well. The question is more on what is a reasonable 'rule of thumb' for the many sizes of aircraft in between ?

Again, I'm just starting back and don't want to err on the too few side, nor do I want to put in more than is necessary (they aren't cheap)...

Example for me: Starting back with a .60 size edge just to get back in the air... one receiver and one remote... well, that is the receiver package that came with the 2.4 module for my old JR 10x (love that radio).

Next, I'll step up to an old BME 50cc Edge I've got laying around and I've got another 30cc 3D plane I may play with....

So... I know there isn't a right or (very) wrong answer. I know some will say, as much as your budget will allow... I understand that. I am looking for your opinions.... For you, how do you make these decisions? What is the dollar cost risk for you...

Thanks for the input and sorry for the simple question...

Well, you'll need a receiver for every plane you plan to regularly fly. That part of your question is pretty easy to answer.

As for transmitters, you only need one if you buy what you need. Since you plan to fly IMAC type planes pretty quickly, I'll suggest going for the 8-10 channel fully programmable transmitters. In no particular order, those would include the Hitec Aurora 9, the Airtronics SD-10, The JR 9503, and the Futaba 10CG. There are other models among those manufacturers, some a bit more fancy and some a bit less, but any of those listed will serve all of the functions you've listed.

Thanks Jester... apparently, my question wasn't clear. Years ago, we would put two receivers in a large plane... split the surface controls up between them..

I assume the same is still being done with these new 2.4 GHz receivers, but I see there are varying numbers of remote receivers... I was trying to understand how you determine how many are necessary for the varying plane sizes... or how you make that determination.

Thanks for in input on the transmitters! Still have much catching up to do... :)

Spektrum is the only company that I know of using remote receivers. Even then though it's not an extra receiver, but rather an extra set of antennas. Multiple receivers aren't generally necessary anymore with the better link that 2.4ghz gives us. With the stronger servos we have now, 50cc planes can do just fine with 6 servos, 7 if you want one for the choke. So a single 8 channel receiver (that allows for an optical kill switch if you want to go that route) will do just fine for any of the planes you've mentioned.

I see the question. I'm flying 2 giant scale a 35% extra 100cc and a 40% sukhoi 170cc. Neither of these aircraft have 2 receivers. I use a smart fly power board. This keeps the voltage to the receiver at a filtered 5 volts while servo voltage is adjustable I'm running 6.5 volts on mine. The board also is an optic kill switch, servo match, and a batt share.
yes you can still have a receiver fail but the chances are slight. With 2.4 interference is reduced.
What must folks I know are running 2 batteries for the system and a seperate battery for igintion
hope this helps.... Welcome back

They are actually receivers.

To the OP, if you're flying Spektrum and you want something redundant get a Power Safe receiver.

BH has the right idea here. If using or planning to use Spektrum or JR then the use of a power safe RX is the way to go. It has dual 16 ga power inputs so getting enough current into the RX is not an issue. They have capability for up to 4 satellite receivers as well and I would suggest using all 4. Now comes the choice, how to power the RX. My opinion would go with the Smart Fly Turbo regulator and smart switch. This reg has dual inputs and outputs and has the advantage of not flowing current through any mechanical switch. You could also run unregulated 6.6V LiFe batteries or A123 batteries through mechanical switches although not my first choice, there are countless airplanes flying just fine with that setup. If your airplane requires servo matching, you can do this with Matchboxes or equivalent, programmable servos or as in the case of my last airplane. I installed a Smart Fly EQ6 Turbo. It has built in regulators, multiple outputs for each channel, servo matching built in and uses a smart switch. In the end it becomes personal preference as to what you feel most comfortable with.

Well with a power safe there's no mechanical switches. The junction box is just that, a power distribution box, the remotes are actually the receivers.

I was under the impression that once the battery was connected to the RX then it was live unless some sort of switch was placed between the batteries and the RX. Is this no longer the case? I had switched from Spektrum to Hitec several years ago so may not be familiar with the current Spektrum/JR stuff.

There's a soft switch that plugs into the junction or central box. It powers up the rx when open. You can replace it with a bind plug, with the bind plug inserted the circuit is closed and the rx shuts down.

If the switch fails open, power stays on.

That makes sense to do it that way. With LiFe or A123 batteries no additional equipment is needed. Then one would just have to choose how to do the servo matching. Thanks for clearing that up. Last time I flew Spektrum in a GS there was no soft switch setup yet. I ran a Smart Fly Turbo reg with a soft switch to give me the warm fuzzies. I personally hate running mechanical switches as I have seen way too many fail.

I'm going to always carry a 2x battery circuit due to an experience that happened to me. I was flying an Airwild 540 Edge, 50cc, with 2x separate switches, regulators and 2x cell LiFe batteries from Duralite. After flying I let the batteries stay in my car for a week. I took them out to charge them as I intended to fly the Edge. Upon charging, 1 pack would only charge to 3.3v. So I knew I had a dead cell in the pack. I can't positively say the cell died in flight but I highly suspect that it did. The other pack charged up normally. Duraflite is sending me another A123 pack as the packs were just over a year old and had not been abused.

Thanks for the input guys !! Lots of good input ! I still have some more reading and catching up to do.. I didn't touch on batteries in my original question. Last time I flew we were still using NiMH.... the new batteries are yet another learning curve.. :)

You'll be happy with a LiFe battery. They charge in minutes, hold the charge for a very long time and are easy to handle.
The Lipos will deliver more current, but are more complicated, you should take them out of your plane to charge and on occasion they tend to catch fire...
These batteries and the LiPo/LiFe chargers are inexpensive, it's money well spend.

LiFe's aren't a fire hazzard at all. Lipos are a very slight fire hazzard if you charge them on NiCd setting or they get shorted or punctured, but there is nothing flammable in an LiFe. They are my battery of choice as well. They give you practically the same voltage as a NiCd or Nimh, with less weight, better durability than Nimh, they can be charged faster, and they can put out considerably more amps. IMO, the A123 version of LiFe batteries are the perfect receiver battery for high performance applications. The flat cell type LiFes are a close second, but they can't quite give you the amps of the A123s and don't last as long.

did not read every reply, but looks like a lot of good advice.

Remember all this new stuff has a learning curve. We can't treat the new 2.4 systems the same as the old 72 band stuff. I have been using the JR system for 7 years and have not had a bit of trouble, but I found out how to handle the JR system.
What ever 2.4 system you get, may have different way to handle that system and set it up.

sticks