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

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.

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

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

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.

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

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

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.

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.

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.

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!

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.

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......
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.

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!

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................

Leardriver

"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

Available using 2 packs in parallel. No other parts needed.


Available using supplied regulators if using lithium. Not needed if using NiMHs. Extra parts not needed.



Dual switches eliminate this as a worry. But there are also "failsafe" switches available that do not require a powerbox.


Never had the need for this. So it solves a problem that does not exist. Did you need servo isolation before?? Have you had problems that servo isolation fixed??


Were you having a problem with this?? I have never seen a problem with a weak servo signal. SO why solve a problem that does not exist??


Matchbox works well when I need this on multiservo installations.

OK, kind of nifty. But since I do not use voltage as my primary indicator of flight time it once again solves a non-problem.


So of your 7 points, only one really seems to be even a little intersting (#7). I know these are the latest greatest, but once again, they clearly appear to me to solve a whole host of problems that no one has documented actually exists. Show me the data!! Show me that the things these devices do are really needed. That's all I ask. Otherwise it is all just sheep marketing.

No

No

Yeah, there are plenty of chances. If you're advocating that one receiver can fail, you're inadvertantly advocating that 2 receivers DOUBLES you chance for experiencing a failure.

Funny, I've never heard of anybody bringing an airplane home safely because they DID have 2 receivers installed. Never, and I've been flying on and off (mostly on) for 20 years. I've never seen someone safely land because they had control of half the control surfaces on their airplane.

Sure I've HEARD of people losing their planes because they SAID there was a radio problem. Mostly, I chalk crashes like that up to pride....it's easier to say it was the radio than to admit you crashed.

I've never not even once experienced a transmitter to receiver problem. Both times I crashed and it was not me just flying the plane into the ground/tree whatever it was the on/off switch that gave up the ghost. In 20 years of flying I've never even experienced a glitch, never, not one.

You're not the only one.

Run 2 receivers if you like it, go right ahead, it'a free country. Just don't stand there and say it makes your plane any safer that a plane with only 1 receiver or the powerbox system. Like I said in my previous post it's ALL a crapshoot. There are steps we can take to make it less of a crapshoot, but NOTHING we can do and NOTHING we can buy that completely eliminates the inherent risk. 6 of one, half dozen of another. Having a PB in my plane makes me feel better, same with the SWB self adjusting rudder servo tray, makes me feel good, is it fullproof? Absolutely not.

Seems like this huge argument over "mine's bigger than yours" is completely irrelavant cuz it doesn't matter the size, EVERYBODY experiences premature e-crash-ulation at least once in their lifetime.

To you only one is interesting.

I'm fine with that, I never said you had to have one to be safe or cool or whatever.

The PB system is not NEEDED. I never said it was needed. I never said it was the only way to fly. I said it addressed problems that existed in MY mind. It makes me feel good, that's all.

Did you even read the entire post? Or did you just knee-jerk react?

Let me re-post what I said.....

Note the word ALL in my final sentence...........

Well, here you go then.

A friend of mine brought his H9 Extra down with only the right side of his plane functioning. It wasn't pretty, but he did get it down in one piece. He was lucky that the side that was still functioning also happened to be the side the throttle was plugged into.

I have been flying since 86 and I have to say this is the only time I have seen a two RX system save a plane. I run single RX myself. And so far, all of my crashes have been either dumb thumbs or structural failure. In those cases I don't care if have 30 RX's in the thing! It isn't going to help.

Steven......Interesting narrative. It all makes sense, as most of my problems have been with brand new or recently crashed equipment. I'll have to give it a try.........

CJ

Interesting blkbird68, I'll have to edit my post to reflect that I have heard of this now!

Never say never!!!!

But like I said it is the ONLY one I have seen saved by having 2 RX's.....

And I think Paul had one saved by having 2 rx's so that would make a total of two that I have either seen or heard about.

I saw Andy Kane land a 40% radiocraft 2 different times on 1 receiver. Ironically it was because the switch plug had come loose from the receiver (using 1 battery and switch per receiver). Using 2 switches and 1 receiver there would have never been a problem.

I think the #1 reason for plane crashes are pilot error, so I think we need redundant pilots <G>

Actually I know of several aircraft that have been landed on one receiver because the other quit working for one reason or another. In fact I know that one of our local guys landed his 3.3M Yak (about $7000 worth of airplane) on one rx earlier this year. Jason Shulman told me he has done it several times and it is basically a nonevent as far as control goes. Chip Hyde advocates it and has claimed to have the system save airplanes as well.

While yes it is rare (thank GOD) that an rx fails...it DOES occasionally happen. I don't buy the argument that it doubles the chance of failure.........I wonder how many of you would choose to fly an airliner equip with a single engine vs two if you had a choice? Oh yea...I forgot....the FAA REQUIRES more than one engine for part 121 use (that means scheduled airlines) because it gives you a chance if you loose one of those very reliable engines. Same damn pinciple.

It is obviously not a gaurantee. S#$t happens that sometimes cannot be prevented and truthfully I am also quit convince that the leading cause of crashes is pilot error, but I am talking about simple straight forward redundancy in my very expensive airplanes and I take exception when a guy like Mike Hurley writes in an article in Flying Models calling me ignorant to do so. I have been at this damn near 30 years and I do know "a little something" about this. But perhaps I am ignorant after all.. I mean it must be correct since it is in the magazine right?

Leardriver

Guys let's watch it with the language. Feel free to be emotional about this topic but remember that you're posting on a family friendly site. 'Nuff said.