ONE RECEIVER OR TWO??
 

i have an aeroworks edge 450 ,33% with a da 100. should i run 2 receivers or one ,and why ?

THANK YOU

RE: ONE RECEIVER OR TWO??
 

I have always run one receiver.
I have my first 33% plane and I am planning to go with two receivers.
While I have never had a receiver fail in the air, I don't want to take the chance and crash the plane. I know the failure rate will increase(mtbf*2), but the chance of a total failure will decrease(Sqrt((mtbf^2)*2).

RE: ONE RECEIVER OR TWO??
 

This topic has been beaten a couple of times. I still cant decide whats best. Receiver failure is a remote possibilty, but a possibilty all the same. I am running one airplane on 1 receiver and a powerbox, and another on 2 receivers. Single receiver is cheaper, and easier to install. With the powerbox I get battery redundancy, signal amplification, and short circuit protection (IMO the most likely cause of receiver failure). With dual receivers I get the piece of mind that if one fails I still have a good chance of recovering the airplane in big pieces rather than little ones. It was a little more complex to wire up, not too bad, the antenna routing takes a little more thought, and some folks claim you lose range - I dont notice it if its true. There is no short circuit protection were a wire to fray or break under vibration - thus the wiring gets a lot more scrutiny than the other between flights - on the bright side there is battery redundancy. If DA ever gets the DPSI Twin in stock, I think thats gonna be the cats meow, hands down the most bulletproof setup. True receiver, and electrical redundancy, all in one box, and it will be going into my dual receiver setup.

Both setups are rock solid. But without a powerbox I would certainly do dual receivers.

Roger

RE: ONE RECEIVER OR TWO??
 

Over 30 years I have lost at least 6 planes directly due to reciever problems. Another 12 or so were close calls, but I got the plane back on the ground in one piece. In that same time, I have lost only one plane due to battery failure.

I bet everyone is running a second battery on their 33% planes.........right? More than one servo for each flight control? But considering a single reciever..........??

A 33% plane is about $3,000. A second reciever is about $150 and 2 ounces. In my mind the math points to adding the extra reciever.

CJ

RE: ONE RECEIVER OR TWO??
 

And you can land your plane fine with 1/2 of your control surfaces (I have done it twice). Replaced an elevator servo, forgot to put locktight on the servo arm and it fell off during flight. Flew approximately 1/2 of my IMAC sequence and some 3D before even realizing that I only had 1 elevator. Also had the same thing happen with an aileron (but from a different reason). Bottom line is that these planes are very stable and if you still have control over one side of the plane you can more than likely land just fine. I know mine weren't reciever related, but if it had been I would have been fine (cell go bad in a battery and one rx goes down, switch goes bad, etc).

my $.02




Hey John... you still alive? Cat ready to swim again?

RE: ONE RECEIVER OR TWO??
 

I GUESS I KNEW BEFORE I ASKED.RECV'RS ARE CHEAPER THAN ENTIRE AIRPLANES .

THANKS TO ALL THAT WERE KIND ENOUGHT TO ANSWER .

AS SOMEONE ONCE SAID,"I MISS MY WIFE........BUT MY AIM IS IMPROVING!

RE: ONE RECEIVER OR TWO??
 

what it the "DPSI Twin" that was mentioned from DA??

Thanks,
Tony

RE: ONE RECEIVER OR TWO??
 

http://rc-electronic.com/html/englisch/englisch.html

Look for the DPSI Twin.

RE: ONE RECEIVER OR TWO??
 

thats going to be VERY expensive!!

why is the dpsi better than just two receivers and two batteries??

RE: ONE RECEIVER OR TWO??
 

Yep, its not going to be cheap.

Why is it better than 2 rx/2batts?
It uses on rx at a time. If that rx fails, its switches automatically to the second, thus *complete* TRUE redundancy is achieved rather than loosing half the airplane (same concept for the batteries), and with only one rx active at a given time, it eliminates the (perceived IMO) range loss of a dual rx system.
It amplifies the signal to the servos.
It provides short circuit protection.
It regulates voltage (selectable) to the servos and the receiver - separately. Can be used with LiPo or NiCad or NiMH.
It allows for the use of two separate rx's on different freqs that can be selected during flight with a switch on the tx, making a very interesting "buddy box" possible.

IMHO, all together in one little box, that is a lot of warm fuzzies on a GS airplane. I dont think the cost is worthwhile for anything under a 40%, but for my $6000 models it seems to be a small price to pay.

Roger

RE: ONE RECEIVER OR TWO??
 

I didn't see a price.
How much are they?

RE: ONE RECEIVER OR TWO??
 

does that mean that you're always using one rx, and one is always the backup and never used??

RE: ONE RECEIVER OR TWO??
 

No, I got my second receiver back from Hobby Services a week ago and I will put it in my plane when I get the chance.

RE: ONE RECEIVER OR TWO??
 

DPSI sounds neat. Trouble is, you're running the whole airplane through a single component.......and if that single component fails.........crash.

RE: ONE RECEIVER OR TWO??
 

Geistware: DA estimates it will be between 400 and 500 bones.

Vatechguy: In principle, yes one rx will be going for the ride as long as there is no failure. If there is a failure, it will be invaluable.

Blowngo: Technically, yes - however if I understand the DPSI correctly, it is a monitor and a switch. Failure of the device would mean you lose redundancy, not the airplane. Loss of the airplane would require a dual device failure. The implied risk vs. the benefit makes it worthwhile.

Roger

RE: ONE RECEIVER OR TWO??
 

As I read the add, it's a battery joiner, voltage regulator, signal comparator, signal amplifier, signal switch, and channel splitter. Am I missing anything? Every wire in the plane is running through a single box, which is modifying the signals and passing them on.

I'd want a little more info before I trusted my 40% to it. That's just me, though.

RE: ONE RECEIVER OR TWO??
 

In the hobby 15 years and have never had a receiver fail. If you isolate the receiver from vibration, and put a piece of tape over the crystal so it can't fall out, and run 2 receiver packs and 2 receiver switches, you've got a bulletproof setup. If you crash a plane, I wouldn't want to stick that receiver in another plane. The receiver components are fragile enough to get damaged in a crash. I have seen batteries and switches fail, so redundancy makes sense for those components.

RE: ONE RECEIVER OR TWO??
 

I'll never go back to 2 receivers again. I just see no need for it. My H9 46% Ultimate ran on 1 receiver with 2 batteries and switches. Perfect right up until I flew it into the ground yesterday [:@]

RE: ONE RECEIVER OR TWO??
 

got pics?

RE: ONE RECEIVER OR TWO??
 

i have a cermark pitts, it runs two y cables (4 aileron servos) on the wings and one on the elevators(2 elevator servos), but i don't want to run y cables and i can't run each servo on there own channals because there are not enough, plus i need an open channal for my smoke, so could i run two receivers and two batteries. Another thing do the receivers need to be pcm, or can i just run standard 8 channal receivers
Thanks
A.D.

RE: ONE RECEIVER OR TWO??
 

Heh.. yep.

RE: ONE RECEIVER OR TWO??
 

Damn Doug, that sucks.

I going with 1 rec and the Duralite Powerbox with the servo programming built in.

RE: ONE RECEIVER OR TWO??
 

DOH!(homer)

that looks like it hurts(your wallet)

RE: ONE RECEIVER OR TWO??
 

Doug,

I so much appreciate someone who will simply say I flew it into the ground rather than try and blame it on the radio, the sun, the electromagnetic flux capacitors in the space station or some other ridiculous excuse.

Thank you!

Better luck on your next one.

Scott

RE: ONE RECEIVER OR TWO??
 

Someone just wrote an article in the AMA magazine stating the opinion that two receivers are not useful and in fact may be harmful due to the increased failure rate and supposedly reduced range. I have heard a bunch of people say that dual receivers aren't necessary in a 33% plane. Okay, then why are they necessary in a 35 or 40%? The aerodynamic loads aren't much different I would guess. The current draw through the receiver is probably comparable. Regardless of the speculation on these two points, I like to err on the side of caution, backup, redundancy so I chose two receivers for my 33% Edge.

Antony

RE: ONE RECEIVER OR TWO??
 

They aren't. Somenzini, Goldsmith, McConville, and I believe Hyde and Hemple all run a single receivers in their 40% and larger planes. So if the very sound technical reasons for not using two RX's are not enough, maybe the above fact is. Maybe not.

Otherwise, run 2 RX's, have a blast and don't worry what other people think. Make your own decision based on what you think is best. Just don't expect everyone to agree with you.

Bill

RE: ONE RECEIVER OR TWO??
 

In the 20 some odd years I've been flying I have never had a receiver fail in any way, not even a glitch. I have had several different (Futaba and JR brand) switches completely give it up though.

The results were total losses on both occasions.

I'm done using Futaba and JR switches.

RE: ONE RECEIVER OR TWO??
 

Bill,

I note that all those guys you mention are heavily sponsored. No question about it, if someone was footing 100% of my bill I'd run one reciever too! Two ounces is two ounces.

On Chip's board he recommends dual recievers with a jumper between them, says it has saved his plane on at least two occasions. Once with a cracked crystal and another with a bad filter.

Jet head......20 years and no glitches.....WOW

CJ

RE: ONE RECEIVER OR TWO??
 

17 out of 21 guys that flew in the last TOC used a dual receiver setup. Jason Shulman told me directly that he absolutely recommends two in anything 35% or larger. I have had a brand new receiver fail and seen several others fail for one reason or another. My $4000-$7000 aircraft will absolutely have a dual receiver setup. I thought what Mike Hurley said in that article was just pure BS! I don't have the article in front of me but I believe he said that anyone that runs two receivers was just "ignorant of the facts"! Really????? So I guess the brand new receiver that failed on me was just my ignorance!! Wow..I'm so glad I now know why there was a bad solder joint on the board.......it was because I was F#@%#$ ignorant!!!! I spose it's just "ignorant" to give yourself a shot at getting your plane down in one piece in the event I do have a receiver problem! Thanks Mike for setting me straight on that one.......

The other interesting thing is that all the guys that argue against a dual receiver setup seem to be JR supporters. Perhaps there is an issue here with JR receivers when used in pairs? Maybe it has something to do with the fact that most of their Rx are single conversion? I have never had any problems or noticed any significant reduction in range when using two rx. I'm not saying that technically there isn't a reduction in range but I would be absolutely shocked if I could fly far enough away to have the "dual receiver range degradation" issue become a factor.

Leardriver

RE: ONE RECEIVER OR TWO??
 

I was also surprised to read what Mike said in his column. He missed a major selling point of dual receiver setups by not mentioning the redundancy that comes with the setup.

RE: ONE RECEIVER OR TWO??
 

OK, you guys win. Two receivers are superior.

Please forgive me for challenging the religion.

And you're right. The ONLY reason that the big names are using one receiver is because they are sponsored and love to take chances, especially when they are competing at the world level. Since they get their stuff for free they can take a chance on losing a world championship or ten's of thousands of dollars at a major event. Can't be any other reason they would do it, could there??

And BTW, I fly Futaba. I have NEVER had a receiver fail (Futaba, JR, or Hitec, flown them all). However, I have had TWO transmitters die in my hands. Anyone up for dual TX's?? They DO fail as well.

Bill

RE: ONE RECEIVER OR TWO??
 

Bill, if manufacturers started incorporating redundancy into their transmitters, I'd be willing to pay a premium for it.

RE: ONE RECEIVER OR TWO??
 

Guys.. the whole dual receiver thing started because we got worried the receivers couldn't handle the current draw created by the ever growing aircraft and hence servo requirements. This turned out to be unnecessary. While I can't speak for Futaba.. I do know the JR 955S is capable of handling a burst of nearly 60 amps.

I only run 1 receiver anymore. I don't feel 2 is necessary.

RE: ONE RECEIVER OR TWO??
 

And to put that 60 amps into persepctive, the folks who make the Emcotec power box wired up a 3-meter plane equipped with 15 digital servos and went flying (3D and precision). They measured a PEAK draw of 26.2 amps as a single spike. Average draw was more like 3 amps. I personally witnessed a JR receiver that was subjected to a torture test that failed at 58 amps continuous. So, as Doug says, the current bearing ability of the RX is no longer a reason for 2 receivers. In fact, it never was. People just did it without a shred of data indicating it was necessary. Sound familiar??


Here's the link to the page with the info I quoted above. Click on the DPSI link and go to the bottom. There is a yellow graph there that you can click on to see better.
http://www.rc-electronic.com/html/en.../englisch.html

And before peole get started, these power box things are another solution to a problem that does not exist. Once again, people are off to the races without getting the basic data required to understand if a problem even exists before they come up with a solution for it.

RE: ONE RECEIVER OR TWO??
 

Wow, I'm relieved. With all of the receiver and hitec servo failures I've been afraid of going to any fly in's in fear of all the planes falling out of the skies <G> I've been running 1 receiver in all of my jets and all but 1 of my 33-40% planes and also hitec 5945's as well without any failures. I ran dual receivers in my composite 40% because of the servo load. Now that I know about the receiver being able to handle that high of a load I'll probably drop to 1 receiver there as well.

RE: ONE RECEIVER OR TWO??
 

Here is some more BS--
once upon a time - I was testing some Rx setups and had stuff scattered all over the bench .
In this mess were two rx -on different frequencies .
I was suprised to see how easily the TX (on one frequency ) -- ran BOTH RX.
OK- why?- cause the RX emit RF .
When the craze for dual rx hit -- I was suprised that many fliers jumped for it -
Anyway - One good rx and some decent power distribution seems to do the job.
For anything up to the "12 servo" setups - I opt for one big ass NiMh (3300 GP 6v) and HD switch and wires - seems fine even for the 8411 servos .
I ain't trying to put the Li power distribution boys in question - I just don't see any real need for these units on 25 lb models .
I see guys wanting to add all of this stuff to 15 lb 1/4 scale BARFS!

RE: ONE RECEIVER OR TWO??
 

I know you're not specifically talking about me when you say "before people get started".........

But let me say this, I chose a Duralite Powerbox for several cumulative reasons not one overwhelming selling feature. The PB is not the be all end all of battery and switch problems but I was tired of haveing $13 switches (Futaba and JR brand) be the cause of complete airplane losses, other than the times when I just flew the plane into the ground. :D

Here are the reasons I chose the Powerbox....

1. battery redundancy.
2. voltage regulation for each battery pack.
3. switching done electronically and not dependent on an actual plastic switch. ANY failure of the switch, the switching fails in the open position.......theoretically......:eek:
4. complete isolation of the servos and leads from the receiver through ferrite chokes.
5. servo signal amplification
6. servo end point and center point programming.
7. voltage monitoring visible ON the aircraft, no pulling out a battery meter and plugging in to read the batts voltage level. Average and lowest voltage seen during the last flight is visible at the touch of a button.


I know ALL of these features are available from other companies. I felt however that having all of them in one unit, designed to work together was safer than having a hodgepodge of different products from different companies wire bundled together in the fuse of my plane. Sure if any 1 function of the PB fails it MAY all fail, but that's no different from the hodgepodge. I'm losing the mess of different colored bundled wires, and about 15 extra connections.

So for me yes the PB IS a solution to a problem that does most certainly exsist, at least in my mind.

Long story short, it can all fail, even the PB! I've made a conscious decision to trust Duralite and the Powerbox system with all those functions. Things in the past I've tried have failed, and things I've tried in the past have worked, I'm betting a >$4500 Comp ARF 2.6 Extra that the PB system works.

That's all any of us can hope for no matter what or who's equipment we choose to use in our planes.

It's all a crapshoot.

RE: ONE RECEIVER OR TWO??
 

I'm using the powerbox in my new Extra for many of the same reasons. Cleaner install, matching technology built in, dual power supply configuration, and so forth. It's not needed.. but I like it.

I ran my H9 Ultimate on 1 Rx with 5 matchboxes, 4 battery packs (including ignition), and it was a ball of snakes inside, but it worked great!

RE: ONE RECEIVER OR TWO??
 

OK, so what you guys are saying is that receivers never fail? Do I have that right? There is absolutley no chance of a bad solder joint, filter, cap, crystal......................anything at all? Wow, that is truely impressive!

Hmmmmm...it seems to me that I have never heard of a plane crashing because the guy had a secomd receiver installed. And you guys have never heard of anybody losing their plane due to receiver failure of some type? I guess I'm the only one................:eek:

Leardriver

RE: ONE RECEIVER OR TWO??
 

"Burn In" is the term used to identify the process of aging electronic components and systems. This Burn In or aging process weeds out inferior components through their premature failure.
Due to the nature of semi conductor components such as transistors, diodes, and integrated circuits, good components can last in excess of 40 years while, on the other hand, faulty components usually fail soon after being put into operation. It is because of this early failure or infant mortality that a Burn In period can increase system reliability and probably save you an airplane.
The Burn In or practice of component aging is required by many agencies, including NASA, the military, and the FAA. Their Burn In periods can last in excess of 100 hours while operating under extreme temperatures and environmental conditions. Generally, the manufacturers of radio control equipment do little or no Burn In and rely on the reliability of the product and quality of the components they purchase for their R/C Systems performance; however, you can do the Burn In yourself and learn something about your equipment at the same time.
Burn In is also a very good practice especially when one purchases a used or pre-owned R/C System or after your system has crashed or spent a week lost in a tree or swamp and been subjected to the elements.
Burn In periods can vary; so let's cpnsider a minimum Burn In of 10 hours. This is equivalent to sixty {60} 10-minute flights, which isn't bad for three nights and very little effort.
Following is a simple procedure.
1. Charge your transmitter and flight batteries for a minimum of 16 hours. This charge period is for a typical charge rate of C/10. Following R/C manufacturer's directions if other charge times are specified.
2. Connect your R/C system as directed and turn it on. As a matter of fact, turn it on and off fifty times if you like. Many failures can turn up here due to transient current and voltage spikes generated during the turn-on and turn-off period.
3. Now, with the system turned on, observe it closely. While operating your sticks (transmitter controls), check to see if all servos are operating smoothly and at about the same speed. Observe the transmitter meter output and make a mental note of its position. For meters reading RF output always check the meter reading in the same way:
a. for RF meters hold the transmitter in the normal flying position with both hands if double stick or cradled in your arm in the normal flying position if a single stick transmitter
b. antenna fully extended. Please do this after dark if you are in close proximity to any R/C Flying area.
c. for meters reading TX battery voltage one can ignore steps a & b above.
If anything is questionable at this point, get help.
4. Record the time. Put the transmitter (TX) down and let the system operate for two hours. On the first Burn In period, check the system every 30 to 45 minutes for servo speed. If the servo speed it slower that in Step 3, turn off the system and recharge the batteries. Reduced servo speed of all servos is an indication of reduced flight pack battery voltage. The speed of the servos should not be preciate. Servos should operate smoothly, quickly, and precisely.
5. Turn off the system after the two hour inspection. Recharge the batteries overnight or until the next day, again, for a minimum of 16 hours.
6. Repeat the Burn In procedure on the second night. Interemediate hourly checks are not required, but more frequent checks are an asset.
Repeat this procedure for at least three evenings.
Here are the results of your Burn In efforts:
Reciever - Every component in the reciever has been excercised to its fullest capability.
Transmitter - All components excercised 100% except the control sticks and the control potentiometers.
NiCd Batteries - have been cycled a minimum of three or four times.
Servos - All servo components are aged with the exception of the servo motors, potentiometers, and the driver-stage of the IC (Integrated Circuit) or servo amplifier driver-stage. These components operate at maximum ratings, only when the transmitter controlls are moved and the servomotors are running. Still, a partial Burn In has been performed on these components. Operating the system controls for an hour will insure confidence in these few remaining components.
Here is what you've accomplished: You've learned how to check your system for normal and thus, abnormal operation. You've developed the bahit of appraising your systems performance. You'll be able to recognize any depreciation in servo speed. You'll recognize any transmitter meter output depreciation should it occur.
You've learned more about your RC equipment and increased your confidence in its operation and performance.

Sometimes, doing things like these work;)