Episode 8: RC Airplane Receivers

[00:00:14] We'll be right back.

[00:00:37] Hello, everyone, and welcome to the RC Plane Lab Podcast. This is Ron. And I'm Tom. Today, we are going to be talking about receivers. I figured this would make sense since our last episode talked about transmitters, so we'll just kind of work our way down the line. And since we described what transmitters did, now we'll talk about what they talk to. Receivers are what go inside the plane and listen to your transmitter. So what do you want to talk about first, Tom?

[00:01:06] Well, probably ought to get started with getting the two to communicate, wouldn't you think?

[00:01:12] Sure.

[00:01:13] So, yeah, it's a process called binding. Unless you're not using Spectrum and you're still using old-school radios with crystals, then there's really not much to it. You just make sure the crystals match the same frequencies, which I don't think too many people use that technology anymore.

[00:01:28] No, but I'm sure there are some people out there that do. And I'm guessing if they do, they probably already kind of know what's going on with the crystals and all that stuff, since you really kind of have to buy everything as a set to make it talk to each other.

[00:01:42] Yep.

[00:01:43] With the newer receivers that you bind together, they, there's no set that goes together. You can make them talk to any receiver, or you can make any receiver talk to any transmitter, as long as it's the same brand, or as long as they're on the same technology, I guess. Yep. Without actually having to change things physically on them, like you used to with the old FM days.

[00:02:06] Yes. Yep.

[00:02:08] Which, by the way, I did look up, there used to be 60 channels on the FM band. Yeah. So that's what I found out. And it looks like they skipped 0.2 megahertz every time to go for the different channel.

[00:02:22] Yes, that was known as narrow band. That was what they changed in, I believe it was 90 or 91. But before that, we were on, I don't think we had 60 channels before that. Because there was a lot of bleed over, the technology didn't exist to really, really hone in that signal and keep it within that bandwidth. So, yeah, 91, I think we all had to put gold labels on our transmitters.

[00:02:44] We had to send them off to the manufacturers so they could, yeah, adapt them to the new standards. And all new radios had to be gold label certified so that they would operate on the narrow band, one of those 60 frequencies. I think I actually have an old, my old X347 back here with a gold label on the back, with a date even.

[00:03:05] That's funny.

[00:03:06] Yeah.

[00:03:06] That kind of dates you, yeah.

[00:03:07] Yeah. But anyway, yeah. So, yeah, you got to get them talking to each other. And the way to do that is through binding.

[00:03:14] Okay. So walk us through it. What do you do to bind your receiver to your transmitter?

[00:03:19] Okay. Well, I'll stick to what I'm familiar with, which is Spectrum. Many of the other brands are similar in the process. check the instructions that come with their unit or Google it. But basically on a Spectrum, you fire up the receiver with a bind plug, which is a plug that basically shorts the first and third pins on the receiver and tells the receiver to start looking for your signal from your transmitter.

[00:03:46] And usually you get an indication of that by a flashing light on the receiver. So you power it up. Yeah.

[00:03:52] So what it does is it pulls the signal wire to ground.

[00:03:57] Okay. There you go.

[00:03:59] Yeah. It's not really shorting it out. Shorting it out is kind of a – when I hear shorting it, I think it's something bad.

[00:04:05] Okay.

[00:04:06] All you're doing is pulling that to ground, looking for a ground reference. That way it knows to go into a different mode when it boots up.

[00:04:12] Okay. So once you've got the receiver in bind mode, then on the Spectrum transmitter, you hold down the bind button while you're turning the switch on. And then the transmitter then goes into bind mode and looks for a receiver that's looking for a signal. And then it pairs with that receiver. However, they communicate back and forth and agree on a protocol and a frequency, if you will, to communicate on.

[00:04:37] And then they agree that they will only accept signals or transmit signals on that frequency. And this all happens really, really fast. And you only have to do it once. I say have to do it once. Something that, we could talk about later. Something that can be done more than once and should be done more than once under some conditions. We'll talk about that later. But, yeah, that's in a nutshell.

[00:05:04] That's once they're bound together, you turn everything off, pull the bind plug out of the receiver, and then you're ready to rock and roll.

[00:05:12] So when you're binding, though, I don't know if they still recommend it or not, but they say you're supposed to be several feet away.

[00:05:20] Yes, that's true.

[00:05:21] The receiver and transmitter should be several feet away. That way I guess it doesn't get overloaded with too much signal.

[00:05:26] Yeah, and you'll get an indication of that because I know on my DX8, sometimes if I'm too close to the receiver, if I'm physically holding the transmitter too close to the receiver, it just simply won't bind. So then I have to shut everything down, start the process over, and get the transmitter at least a few feet away from the receiver, and then it usually binds just fine. But it either binds or it doesn't. There's no half binding or partial binding or anything like that.

[00:05:59] It either binds or it doesn't. Yep.

[00:06:02] Okay. See, I didn't know if it had anything to do with the amount of signal that was there.

[00:06:07] No.

[00:06:08] Because I remember I had one. It was a spectrum receiver. It was a little park flyer.

[00:06:13] Okay.

[00:06:13] That I lost signal on. And that was before I knew how to bind. And I was really close to binding or really close together when I was binding it together. Okay. But, and I don't know if this is true or not, but I remember after that happened where I lost the airplane because I lost signal, I was looking somewhere online. And it said something about that it's very important, especially for park flyers, to be bound, binded, bound, I don't know, to be bound from a farther distance.

[00:06:46] Like I said, I don't know if that's true or not, but I did have a problem. That's the only one I've ever lost from losing signal. It's not like it was far away. Actually, you were flying it when it happened. Do you remember that one? That little. The pizza box.

[00:06:58] Yeah, the little flat guy.

[00:07:00] White little.

[00:07:00] Yep. Yeah. I do remember that.

[00:07:02] I love that airplane. That was a good airplane. Yeah. Yeah. I miss it.

[00:07:05] I'm sorry.

[00:07:06] But anyway, no. So that was the only one that I ever lost because of that. And like I said, after that happened, I did look it up and it said that when you bind those, it's supposed to be done at a farther distance. There's something special, according to that one thing, about park flyers. And I don't know if that's true or not, but just something to keep in mind. Okay. Always keep, a good 10 feet just to be safe when you're binding, I think.

[00:07:28] Okay.

[00:07:29] That's kind of the rule I've gone with now when I bind new things together.

[00:07:31] That's interesting because the bind process shouldn't have anything to do with range.

[00:07:39] Well, and it could very well be that it didn't. But, like I said, that was just something I came up with after that when I looked it up. And it could be complete bunk. That's not true. But, best practice, go ahead and when you bind things, just have a few feet between the two.

[00:07:54] Yeah. And then you can also perform a range test with spectrum transmitters by pressing the range test button, which reduces the output of the transmitter. And then you walk, I forget how far it is, I think 30 feet, I think, is what they recommend, and operate all the channels. And if everything is working, then, you've got a good, a good pairing, if you will.

[00:08:18] Okay.

[00:08:19] Yeah.

[00:08:19] That's a good idea, too, I guess.

[00:08:21] Yep. I do that on every new installation, not necessarily a new model. If I pull a receiver out of one airplane and put it in another one and rebind it, anytime I rebind or bind a receiver, I perform that range function test before I fly it. It's just, one more thing, kind of like a good pre-flight, one more little piece of insurance.

[00:08:44] Yeah. Good idea. Good tip. I'll be honest, I don't do that. So I probably ought to start with some of these things, and maybe that would have caught that one problem I had. Maybe.

[00:08:54] Maybe. You never know.

[00:08:56] Yeah. And it could have been a brownout. It could have been, anything weird going on with it, and I just don't know. Actually, I still have that receiver in a box, and it was a Spectrum receiver. Maybe I ought to send it back in to them and let them look at it and see if there's anything wrong with it.

[00:09:11] Yeah. My guess, though, is if it's a Park Fire receiver, they probably don't support those anymore, or at least not that one. But you never know. I mean, you could certainly wouldn't hurt to get an answer, at least.

[00:09:23] Yeah, because I don't plan on using it in anything else. So it's just kind of sitting there taking up room. Right.

[00:09:28] Right. Yeah.

[00:09:29] Might not be a good idea. So, yeah. I didn't know you could do that until you taught me that, to send them back in when something goes wrong with it. See?

[00:09:35] If anything has come out of this episode, you've learned something. So there we go.

[00:09:38] There you go. Yeah.

[00:09:40] So, yeah, once you've got them talking to each other, the transmitter and the receiver, then you have to start, telling the receiver what to do, right? Assigning channels.

[00:09:50] Well, actually, hold on. Before we go too far, I want to mention when you bind. So there's a battery slash bind port on most of these receivers, at least the ones that I've dealt with. So when you bind, you can actually put your battery in any port.

[00:10:07] That's correct. So, yeah, you don't have to worry about.

[00:10:11] Yeah, on spectrum. Because so the way those work is they have their power bus to where all of the negative and positives are bused together. So every one of those pins is run off of the same connection. So when you power up, if you put the battery in the aileron port, they're all going to be hot. They're all going to have the negative on them, too. So you're going to have ground and positive. So signal is the only thing that really changes all throughout them.

[00:10:40] So when you're going ahead and binding it, you can put that in any port as long as the bind plug is in the bind port.

[00:10:47] That's correct.

[00:10:48] So I just want to make that distinction, too.

[00:10:51] Yep, yep. Yeah, that's a good call because I'm actually looking at one of my old AR7000 receivers, and it doesn't have a bind port. It has a battery port and all my channels, but no bind port. So in this case, you plug the bind plug into the battery port and then plug your power source into any of the available channels to do the binding. Yeah, and your receiver, when you buy a receiver new, it'll, of course, come with instructions that tell you how to do it.

[00:11:22] But in general, if there's not a bind port specifically on your receiver, the battery port will be the function you use to set the, to plug the bind plug in and set the binding process in motion. And then, like you said, you can power up a receiver in any of the available channel slots because they'll pick up power. Okay, I got you now. From any of those feeds. Yep.

[00:11:46] Cool. Got it. Yep. So what's next?

[00:11:50] So, yeah, like I said, once you've got them communicating with each other, you have to start the process of plugging everything in and using up all those channels that are on there. Did you want to talk about channels?

[00:12:03] Yeah, so a normal, I don't want to say normal. The basic, really, amount of channels you want to fly with, I would say, is four. I agree. You can get away with, yeah, you can get away with a three-channel receiver. Three-channel receivers will control throttle, rudder, and elevator. Going up to the four-channel is when you get the ailerons. So…

[00:12:25] Well, technically, they don't have to be those channels. Like a three-channel, which I'm not even sure you can buy a three-channel radio or receiver anymore, but it doesn't necessarily mean throttle, aileron, elevator. It could be throttle, rudder, elevator. It could be Elevon, throttle, and, I mean, who knows? But just because the… I did want to touch on that.

[00:12:48] Just because the channel is labeled, for instance, on my AR7000 here, the very first channel at the bottom is throttle. Well, just because it says throttle, it's still a proportional channel. It can do whatever I want it to do. But it is set aside, and the programming in the transmitter will match throttle when you go looking through the menus, if that makes sense. Yeah, I just wanted to…

[00:13:14] Okay, so thanks for the correction. That's fine. And you're right. I guess what I'm talking about is basic airplanes. Like, if you're just out looking at an airplane, a normal three-channel airplane slash receiver will normally control your throttle, your rudder, and your elevator.

[00:13:29] Exactly.

[00:13:30] Yep. So, when you go to the ailerons, that's when you get your fourth channel. But you're right. You don't necessarily have to have those for those channels. Right. like we talked about before, dihedral. If you have a big enough amount of dihedral built into your wing, you really don't need elevator… You really don't need ailerons because it will kind of self-correct on its own. But it's… Once again, I just want to say that it's good to get used to four channels.

[00:13:58] Absolutely. And just kind of stick with four channel and don't go anything under.

[00:14:01] Yep. I could not agree more. Yep.

[00:14:04] Yeah. And so, when you go up to like a fifth channel, most of the time, that's going to be like a gear, landing gear that are retractable.

[00:14:12] Or flaps.

[00:14:14] Or flaps. Yep. And then, yeah, your sixth channel is kind of going to be flaps or gear, too, is usually what stuff is used for. Now, you can… If you don't have landing gear that retracts or if you don't have flaps on your plane, you can use it for a lot of different things.

[00:14:27] Exactly. Yeah, I was just going to say that.

[00:14:30] Right. And sometimes, too, if you just have six channel, you might need more than six channels to do six things. your gear… Or not your gear, but your flaps. You might want to have separate flaps to be able to control your flaps separately. And then maybe you can mix that with ailerons. And so, you have, your flaps would also go up and down with your ailerons. But then, when you flip the flap switch, then they go down.

[00:14:55] So, I mean, there's a lot of different things you can do based on channels.

[00:14:57] Right. And I think it would help. I mean, so, channels… I mean, that used to be how we thought of functions on an airplane. an aileron is a channel. An elevator servo is a channel. Anymore, at least on modern, radios that can do the mixing and stuff like that, we use channels a little bit differently. Like, you kind of touched on, flaps and operating them separately. Like, lots of airplanes use multiple servos to drive ailerons.

[00:15:32] So, I mean, I've got several airplanes myself that I have a servo in each wing panel to operate each aileron independently. And that takes an extra channel on the receiver if I want to operate them independently. Yes, you can drive them with a wire harness on one channel, but you're not truly operating them independently.

[00:15:54] So, that's how you're going to get your flap around function to work, for example, is you'll have to use up another channel or slot on the receiver because you're then going to plug that second servo in the case of Spectrum. I think it's the right-hand aileron servo will plug into that sixth, if you will, channel or slot on the receiver. So, yes, they're channels, but really, they're really more just plugs and independent functions.

[00:16:27] So, I mean, it can be kind of misleading when you say, yeah, I fly a four-channel airplane, but I'm using eight channels. what I'm saying?

[00:16:37] Yeah, yeah, I understand.

[00:16:39] So, that kind of helps the discussion sometimes, especially if you're going, searching for a receiver to buy, let's say.

[00:16:49] I always say buy as much receiver as you can afford, not necessarily what you need because I can't tell you how many times I've run out of slots or plug, except receptacles on the receiver because I'm using so many different servos to do this or do that or, mix, Flaperon or Elevon or Ailer Vaders or whatever you want to call it.

[00:17:17] Yeah, but most of the time when you're building a plane, though, you kind of know what you're going to be doing.

[00:17:24] Yeah.

[00:17:25] So, I mean, I don't have, like, a bunch of extra receivers sitting around waiting for airplanes. So, I will buy a receiver for an airplane as I'm building it or putting it together or whatnot. And then when you kind of look ahead and know what you want it to have, then how big of a receiver to get.

[00:17:46] But most of the stuff I get is going to be six-channel, even if it is just a regular four-channel airplane or, one that controls your ailerons, elevator, rudder, throttle.

[00:17:58] So, here's a great example right here on my building board. Well, hold on. Okay.

[00:18:02] Hold on. That's fine. Let me finish this, my thought. What I was going to say, though, is, even though most of them are four-channel, I have used the fifth channel, even if I don't have flaps or retractable gear, for, like, onboard glow heaters.

[00:18:17] Okay.

[00:18:18] You can use that. Or if you have a gas engine, you might want to use that for your choke, if you don't want to have a manual choke.

[00:18:27] Or a kill switch.

[00:18:28] And you can, I was going to say that, too, or a kill switch. And that's not a bad idea if you're working on a gas airplane to be able to turn it off remotely. So, like, the opto-kill switches are a good idea. most of the time when you're working on, like, a nitro plane, you can just shut that throat all the way down, and that will kill the motor. So, I've never set up a gas plane to do the same thing. I don't even know if you can or not.

[00:18:53] You can.

[00:18:55] Oh, you can? Yeah. Okay. Well, then, maybe next time when I set up a gas plane, that's how I'll do it. But I usually put the kill switches on it.

[00:19:00] I don't recommend setting it up that way, but you can.

[00:19:04] Oh, and what's the, so, not to get off topic too much, but what's the issue with doing that?

[00:19:12] Well, I mean, if your linkage gets bound up in the airplane, then you have no way to shut it off. For one thing, unless you have an opto-kill switch, then that could be dangerous.

[00:19:22] If you're on the ground, let's say, and you're going through your startup process, and you don't have an opto-kill switch, and you're not exactly sure where the throttle is set, and you go to fire the thing up and runs at half throttle and takes your arm off, that's another good reason to have an opto-kill. So, I mean, there's lots of reasons not to set up an airplane that way, but anyway. Okay.

[00:19:46] All right. I'm just curious, so go on.

[00:19:49] Yeah, so what I was going to say was, the example that's on my bench right now, this Horton kit, I mean, it's a fairly simple airplane. It's a flying wing with two electric motors. But even with a Spectrum DX8 and an eight-channel receiver, I'm out of, I've used up all the slots, and technically, I have the flap servos on a Y harness because I don't have any more slots that I could use.

[00:20:20] So, even simple airplanes, depending on how you're driving the control surfaces and what other function, if I wanted to put lights on this airplane that I could control from the transmitter, I simply couldn't because I'm out of, I've got all my servos and the two speed controllers, they're all, all the slots in the receiver are occupied.

[00:20:41] So, I always, I mean, I will always tell people, if they're shopping for a receiver just to have or for their next project, buy as much as you can afford because, I hang on to airplanes for a long time, but I also, trade and whatever, somebody likes an airplane I have, I'll pull my radio gear out of it.

[00:21:04] Well, now I have this radio gear, and if it's a six-channel receiver, well, now I'm limited to putting this in a, in an, in an airplane with six servos or five servos in an electronic speed controller or whatever. I'm limited. I'm limiting myself, and I have an eight-channel transmitter, so why not at least have an eight-channel receiver so I can, so I can use all those functions if necessary.

[00:21:28] Just, just something I, yeah, just something I, I try to, I try to do whenever I can. If I'm, if I'm picking up a receiver, I'll, I'll try to pick up whichever, whatever, whatever is in the budget, and, and maybe then something if I can.

[00:21:42] Yeah, well, and I get that. I usually, like I said, just buy what I need for the airplane I'm working on.

[00:21:47] Right.

[00:21:48] And I, I don't really think ahead that way. And it, it really hasn't bitten me too much because most of the stuff I'll, I'll buy is going to be like a six-channel. I don't necessarily buy four channels very often.

[00:21:59] Right.

[00:21:59] I guess that does give me a little bit of extra leeway in case I need to add something to it. But yeah, most of my stuff is six-channel. I have some seven-channel, eight-channel, but most of the stuff I have is just six.

[00:22:10] Yeah. And, and honestly, most, probably 90% of the airplanes I fly would be just fine with a six-channel. And in fact, I mean, I, I don't, I'm looking around the shop here. Well, I've got the Kristen Eagle. I think I have it set up with eight channels. But yeah, I mean, six channels will fly 90% of the airplanes I own. But it's just nice to have that, those extra channels, when the, should the need arise.

[00:22:35] Yeah.

[00:22:37] Buy, buy what you can afford for sure. But if you can afford a little bit more, I always say, go for it if you can.

[00:22:45] Yeah. And, and I understand that. So like one of the other considerations too, though, is like for my, my big yak, I actually fly that on an eight-channel receiver, even though I have a lot of servos in it. Right. And that's because I use one of those smart fly boards. Would you want to go ahead and explain kind of how those work?

[00:23:05] Yeah. So a smart tray is, is basically nothing more than a power distribution center, if you will.

[00:23:13] Your receiver is still doing the receiving function, receiving the signal from the transmitter and then sending it, in this case to, to a power distribution center, which allows you to plug in multiple servos on, there, there's lots of different ways and lots of different boards out there, but essentially let you, if you, if you want to think of it as ganging servos up on one channel without using all the wiring and the Y harnesses and all that, it's a nice, cool little board with all of these plugs that you can plug into.

[00:23:47] And then you run a, a lead from your receiver to that particular channel on the board. And then the board divvies that up to the servos. Usually, they, they also provide provisions for optical kill switches that are built into the boards, which are pretty sweet. they also offer, multiple, power sources to be plugged in. So you have redundancy built into the, especially like on your yak, you can use, I think it's two, receiver batteries.

[00:24:21] So you have that sort of redundancy and that extra capacity to drive those high volt or, high volume power hungry servos. so that's kind of what a, what a power board or a smart tray or a power distribution block or, or whatever you want to call it, is it, is it allows you to, to really, really gang up those servos on those big control surfaces without using up a lot of slots in your receiver.

[00:24:46] And so what I like about that too, though, so you're, you're correct. I'm not powering anything through the receiver. Right. The only thing, the only power the receiver sees is from the batteries that go into the smart board and then that handles all the, the, the higher amperage, draws.

[00:25:07] I should have said that, but yeah, exactly, exactly what you said that the, the power is not going through the receiver to drive all those, those heavy duty servos. The power is actually going through that board, which is built very robustly to handle that current. Yep. Exactly. Yeah.

[00:25:22] It's, it's made to do that. Yep. And the nice thing I like about them too, depending on what kind you get, they will actually have separate end point adjustments and, for each servo. So on my yak, there's, there's two servos per aileron.

[00:25:36] Okay.

[00:25:36] And I used to use match boxes on those. So it's a, what a match box was, it's a little, I think JR made it and you can, you have one input going into it and then it, it matches the servos. So a servo, even when they're close, they really don't put out the exact same, position. And that could be just how you have it set up. if you have your clevis just a little tighter on one than another, the, the, the actual position will not be exact.

[00:26:07] And you don't want those servos to fight each other. You want them to work perfectly in unison with each other. So they're not, so they're not trying to change the other one's position.

[00:26:16] Right.

[00:26:16] You don't want, you don't want any torque. You don't want any, twist in that aileron as, as you're, as you're flying. So what they do is you set your end points, your, your full throws on them so that they're not fighting each other. And, and you can do that in the match box, which is, like I said, it's just a little box that, it's really not much bigger than a receiver.

[00:26:40] And then usually those sit, I don't remember if I had those in the wing or if I had them in the, in the fuselage. Yeah.

[00:26:47] It doesn't matter. Yeah.

[00:26:49] Yeah. So the, the smart board though gets rid of those. And the thing I like about the smart board though, is it also does the, the, the matching, the end point adjustment and all that. So they're not fighting each other. but it just makes the whole inside of the plane look so much nicer.

[00:27:04] It does.

[00:27:05] Yep. So you have single wires that go into the receiver and it just, it makes the whole thing look a lot cleaner.

[00:27:11] It does.

[00:27:11] The installation looks nicer and it really works better in my opinion. so, we talked before about the, the power bus that's in the receiver. Those are only made to, to handle so many amps. Exactly. You don't want to pull a whole bunch of power through them. If you do, you can, overheat them, you can burn them up.

[00:27:31] You can have a lot of issues, with, even with the smaller airplanes, because some of these newer servos are actually pulling quite a bit of power through them.

[00:27:39] Sure.

[00:27:40] So make sure you're not overloading, overloading your, your receiver with it. And, and what happened, that's what happened to my plane when I almost lost it that one time to that big yak is that, I think it was pulling too much power, through that receiver. And then it just shut itself off and, and reset itself because it was just pulling too much through and it just kind of, freaked out.

[00:28:04] Yep. Saw a low voltage and browned out. Yep.

[00:28:06] Right. Which I'm, I'm okay with that. I'd rather have it do that than actually, catch on fire or mess something up inside of it. True. so, with, with the running the smart boards in there, you're able to control the power where it's going. You're able to control the signals much better. cause like I said, on, on not only do I have two, two, servos per aileron, there's two servos on the rudder. There's two servos for the, the elevator.

[00:28:34] So there's, there's a lot going on in there.

[00:28:35] Right.

[00:28:36] And a lot of electronics going together, working to make those, those actually work in unison and not fight each other. So smart boards, if you have a big airplane are a good thing to have, I think.

[00:28:46] Yeah, I, I agree. Especially if you're using, like you said, using those high voltage, or I'm sorry, those high amp draw, servos and multiple power sources, they really do clean up the installation.

[00:28:59] Yeah. And it's nice to be able to power it off of two batteries too, completely separate.

[00:29:04] Yep.

[00:29:04] If you have a problem with one battery, you still have that other one in there to kind of help.

[00:29:08] Right. So I, I, I wanted to mention, I hate to go backwards, but, binding.

[00:29:16] Yeah, cause I wanted to say something about that too, but you, you might be on the same page as I am.

[00:29:21] Well, yeah. What position the sticks should be in when you bind?

[00:29:25] Yes. Yeah. Pretty much. Yeah.

[00:29:27] So usually, during the construction of an airplane or, or, or an ARV or anything that you're going to, install your own radio in, you'll have to, bind your radio system together so you can start using it and then you'll, you'll install your servos and then you'll set up your linkages and all that stuff. And on that first bind, your, your goal is to get the transmitter and receiver working together and that, that's fine.

[00:29:56] But once you have your airplane, especially the control surfaces set up, you'll want to bind it again. And, and Spectrum, I think Futaba offers something similar, but Spectrum offers a, or they don't offer, they build it into their system. oh gosh, I just, the name of it escapes me, but it's a, it's a kind of a, a safety device that's built in such that.

[00:30:20] It's kind of like a fail safe.

[00:30:21] Fail safe. Thank you. That's it. yeah. That is sort of built in that will drive the servos to a predetermined position. in the case of a, like we were talking about your yak with the brownout, and, and that those positions are set during the bind process. So, you, you, you've bound your radio and you're setting up your control linkages. And this is especially true for throttle, and especially on electric airplanes.

[00:30:49] You want to, when you get everything set up and, and you, you've run, you got your airplane built and all the linkages are the, or the, where you want them and everything is standard. You really ought to rebind everything with those sticks on the transmitter in a position that you want those servos driven to in the case of a, a signal loss or a brownout or, or, or something, wrong during the flight. And usually those positions, low throttle.

[00:31:17] And if you want, maybe a little bit of up elevator and maybe some right, I don't know, whatever, set the plane up in a shallow, glide. I turn and glide or whatever. and those positions are set during the bind process. So, like I said, when you're all done and, and the airplane's good to go, you're all finished, you're proud of your work, go back there and rebind it, with the sticks in those positions. Cause that's very important.

[00:31:41] And that's often, a step that gets overlooked. And I know I've overlooked it many times, and I go to the field and I turn the transmitter on and I turn the switch to the, to the airplane on and the servos go, crazy in one direction. I'm like, Oh, I forgot to, I forgot to bind it in my fail safe position. So just something to think about.

[00:32:00] Yeah.

[00:32:00] So the Brownall story reminded me of that. Sorry.

[00:32:03] Yeah, that's right. And it's also very important to remember if you ever reverse the direction of a servo to rebind, especially if it's throttle. yeah, I think we, we both, we both know the same person that had an issue with that. he had an issue to where, he got it all set up and got it running great, but the throttle was reversed. Right.

[00:32:25] Well, I laugh. I've done it too. I can't laugh at that image. I've done it myself. So yeah.

[00:32:31] Well, but yeah. And then, and then what happened was he lost signal and instead of going to, going all the way down to an idle, it was a nitro plane and it went to full throttle and it just flew away.

[00:32:45] Yeah.

[00:32:46] So very important to remember to do that. and, and the other thing, when you're, when you're going to the fail safe, like what I always do to check it, and I don't know if this is the right way to do it or not. electric gas doesn't matter what kind. So I will act like I'm doing my run up, when you're, you're standing, oops, when you're standing over the airplane with your, with your feet, holding it to make sure it doesn't go anywhere.

[00:33:13] Right. I will just turn my transmitter off.

[00:33:15] Yeah. That's one way, one way to test it. I prefer to do that with the engine not running, but yeah, that's, that's a way to test it. Yeah.

[00:33:24] I mean, right. So, I mean, if it's an electric one, you obviously can't turn the engine on or off. I arm it and I do all that kind of stuff. But when I'm, when I'm just checking to make sure everything is set up right, before I, and this isn't done every time. I'm just talking about when I, when I set one up. so it's not every pre-flight I don't do that, but it's after I get it all bound together and get it and get it set up the way I want it.

[00:33:45] I'll just, sit there and turn it off and make sure it works right.

[00:33:49] Yep. Yep. Yeah.

[00:33:50] That's, that's it. That's very important because, if you're working on a little electric one and you don't have that set up and it's in your basement or something like that and you have it plugged in and then you don't think about it and you turn your transmitter off first and you have it not bound correctly with fail safe, then you're going to go full throttle and you can really get hurt. Yeah. Yep. especially like I said, if it's an electric one.

[00:34:13] So it just makes a lot more sense to do it the first time, make sure it's done right and then always rebind it, with the fail safe the way you want them.

[00:34:22] Yeah. No, I agree. Yep. So do you want to, do you want to, I mean, we talked about AS3X and safe in our, our other episode. Did you, do you want to hit on that again a little bit?

[00:34:35] Yeah, I think that's a good idea. because that technology, lives in the receiver.

[00:34:42] Absolutely.

[00:34:42] So, you, not only do you get that when you buy an airplane that has that built in, but you can buy AS3X receivers. and then, those are very important to read the directions. Yeah. Because they have to be put in correctly.

[00:34:58] Yeah.

[00:34:59] Anytime you have a gyro in there or something like that, that it has to be, there's usually one way that can sit in an airplane and work. If you do it wrong, you're going to crash.

[00:35:07] Right. And, and like we mentioned in the other episode, they, they, after a little bit of research, don't, don't mount your AS3X receiver with Velcro.

[00:35:16] Right. Yeah. It needs to be a little bit too much. So that's, that's good too.

[00:35:20] Yeah. It needs to be a good solid mounting. And like you said, it, it, there's absolutely a direction, or, or several. Usually I think, the last AS3X I saw, there was like three or five, acceptable mounting positions and nothing else. So, yeah. Read the directions. Yeah.

[00:35:41] I've never actually, used one of those and I, I don't necessarily think I plan on it either.

[00:35:46] Yeah. It's not, it's not something that, that I'm terribly interested in, in, in purchasing. If it, if it comes with a, with a foamy, then, so be it. But, it's, it's not a, it's not a technology that I'm, I'm going to seek out because like we, like we said before, it's, it's really a, a designed to be a, a tool to, to assist new pilots, to, to, to become proficient flyers.

[00:36:12] And I feel like I'm a fairly proficient flyer, so I don't need the stabilization, but it does

[00:36:18] Have a. You've only been flying for what, like 90 years now. So, yeah.

[00:36:21] It's not quite that long, but, I mean, on the, on the small foam airplanes, yeah, I guess, I had that little, that UMX, e-flight beast that had that technology and it was pretty cool. It would, on a windy day, I could fly that thing and it looked like there was no wind out there, but, I'm pretty confident that, I didn't need that to at least fly the airplane. But anyway, yeah.

[00:36:47] And my only, I guess my only other problem with those is I, I don't want it to give somebody a false sense of security that, well, this is how a plane flies. So I'm okay. Oh, it's 15 mile an hour wind, but that's all right. I've done this before.

[00:36:59] Yeah, exactly. Yep.

[00:37:01] I, you have to watch what you're doing and know your skill level.

[00:37:05] Right.

[00:37:05] And don't rely on the airplane to do it for you.

[00:37:08] Exactly.

[00:37:08] That's my two cents. Take it for what it's worth. But, I agree. I prefer to be the one. Yeah. I prefer to be the one in control completely. Yeah. So that's, that's just me.

[00:37:19] Yep.

[00:37:20] And then, for flying for the hobby. I mean, I really think they're cool when you can program the takeoff and, and land on their own and do all that with drones and all that too, I think is, is neat setting the waypoints and watching it fly, go to different heights and all that. But that's, that's not, that's not the hobby that I enjoy.

[00:37:36] And, and really, that's really not the scope of, of this podcast anyway.

[00:37:41] No, correct. So that's, yeah. Sorry, we shouldn't talk about that.

[00:37:44] My bad. No, that's okay.

[00:37:46] And then, and then. Thanks for scolding me.

[00:37:49] The, the safe technology is, is, is kind of, kind of the same, but different. It's, it's a tool designed to, to get people, flying, with, with little or no experience and, same kind of deal. You can buy safe technology, I think, off the shelf and you can also get it in, in ARFs and things like that.

[00:38:11] I see, I didn't know you could get it on, in a receiver off the shelf. I think. That's, that's good to know.

[00:38:16] Yeah. I think, well, I, I can't say that to any certainty cause I haven't, I haven't sought it out to, I had a, an ARF that had it. In there and I didn't particularly care for the airplane, so I, sold it or traded it or whatever. But, I believe you could buy that receiver off the shelf..

[00:38:37] And what airplane was that, by the way?

[00:38:39] I believe it was a Hangar 9 P51, I believe.

[00:38:43] Oh, you got rid of that one?

[00:38:44] I did. Yeah. Yeah. I did not know that. I think.

[00:38:48] That was one, that was the one I thought about getting off of you. That's been a few years ago.

[00:38:53] Yeah. It had the little 10 CC gasser on it. Ran really, really good. Yeah. It was a.

[00:38:58] Yeah.

[00:38:58] .

[00:38:59] I remember you flew that at the, the Warbird flying and stuff. That was a good one.

[00:39:03] Yeah. Yeah. it didn't fly bad. It just not, it didn't fly in my opinion, like a P51 should. And it wasn't designed to, it was designed, more or less as a, as a second airplane, kind of a low wing trainer to get people away from trainers and into airplanes that look like airplanes.

[00:39:22] But, yeah, that was kind of what, that was kind of what took me away from that one is it, it was a good looking airplane, but it didn't have that actual, P51 shape to it. they, they, they fudged a little bit here and there to kind of make it fly better, which is, that's cool. I understand that was the point of it.

[00:39:39] No, exactly.

[00:39:40] If you want to scale P51, that's not what you're going to get. And that's kind of what I didn't like about it. Right.

[00:39:44] But it, it did, it did fly good and it did look good in the air and the engine ran good and all that, but the safe technology wasn't really, for me. And it was, in my opinion, on that particular airplane on its highest setting, I don't believe if it was flying away from me, I could get it to turn and come back to me. It was limited that much. oh wow. Yeah. I mean, I don't know how it does it.

[00:40:14] I'm sure it does it with gyros, built into the receiver and all that. But I think on its, on its most severe setting or most corrective setting for lack of a better word, it wouldn't let it bank more than 10 or 15 degrees.

[00:40:28] So yeah, if it was flying away from me and I needed to turn the thing around, especially if I needed to turn it around quickly, to avoid a, say a tree or, flying over, populated area or whatever, physically with the stick buried to the right or the left, it physically would not turn enough. So I, for that reason, you could turn that off though, correct?

[00:40:50] You could. I mean, like completely off.

[00:40:52] Yeah, you could. but the airplane just wasn't set up to be aerobatic, but anyway, that's not what we're talking about. okay.

[00:41:00] The, only other thing I think I want to talk about them before we, before we get off here.

[00:41:07] Okay.

[00:41:07] Remotes for the receivers.

[00:41:11] Okay. Like satellite receivers.

[00:41:14] Yeah. Like satellite, remote receivers, whatever you want to call them. Satellites. Sure. Remotes. Yeah. I've heard it both ways.

[00:41:19] Yeah. Spectrum and Futaba both use them.

[00:41:22] And so what's the point of those?

[00:41:25] Okay. So on the, on the receivers, let's say we're talking about a regular rolled four channel receiver, no satellite, receivers, plugged into it or anything like that. It has the antenna, coming right out of the receiver and our spectrum, our DSM specifically receivers have really, really, really short antennas because the signal is so good, right?

[00:41:47] It doesn't need these long antennas like we used to trail out the back of our airplanes or make them, you remember.

[00:41:53] Yeah. I've seen pictures. Yeah.

[00:41:55] Yeah.

[00:41:56] Never owned one like that.

[00:41:57] Right. Right. My, my, my, my poor contender here has got, has got a, still got a scar on the side of the fuselage where the antenna used to come out. But anyway, so they're, even though they're really, really, really good, they're, they're kind of limited. I don't want to say limited. That's not, not the correct word, but they, they can only, they only gets a clear picture because the receiver is usually buried in the airframe, right?

[00:42:25] We don't stick our receivers on the outside of the airframes. So therefore the receiver antenna is also inside the airplane. So at some angles, that, that the receiver, when you're flying around, obviously we don't just fly straight and level all the time. We like to do loops and rolls and spins and all these other things. Occasionally during some of those maneuvers, we may not present the best target for our transmitter to send a signal to.

[00:42:50] And what I mean by that is the antenna may not be in a prime position to receive the signal from the transmitter.

[00:42:58] And yeah, so they, when they should be parallel to each other, when you're flying. So to get the best transmission and the best signal to your receiver, you don't, if you're looking right at it, you don't want that wire to be pointing right at you. Exactly. You want that wire to be 90 degrees from you.

[00:43:16] And same, by the way, we didn't cover this, but same with the transmitter when you're flying it, you don't want, they, they bend those, the, the antenna bend. So that is because you want to be able to, they do on ours, the new, new transmitters,

[00:43:31] They don't bend at all.

[00:43:34] Well, I guess that's true. They have, they have such a better and smaller antennas in there even that work. But for those of us that have some of the older ones, when, when you do have that bend and to make sure, and this goes for any antenna, even like if you're trying to set up your home internet, when you're working with your routers and, and, and such, you want those antennas to be broadcasting.

[00:43:54] It's, I don't know how to describe it very well, but it's, they, they, when it, when that antenna is sticking up, that is when it broadcasts around it. So it doesn't broadcast out the end of it. It broadcasts around what the, like the, how the antenna is pointed.

[00:44:11] Right.

[00:44:11] So always make sure you kind of bend that antenna. That way you get better coverage.

[00:44:15] Got it. okay. So, Spectrum, what they did, to help alleviate that problem of, of, end to end transmission, let's just call it, which would be the weakest link between the two, right? As you can plug a, another additional small receiver essentially, into your main receiver that has antennas attached to it, that you can then position in a different plane, if you will, and not by plane, I don't mean airplane. I mean, a different plane of reference, right?

[00:44:51] So for instance, if I've got my AR 7000 here mounted flat in the bottom of my fuselage with the, with the antennas pointing out, towards the left and the right, I can then plug again, a satellite receiver, run it to a different part of the airplane, depending on how long my lead is, and then orient those antennas 90 degrees, ideally, to the antennas that are on the main receiver.

[00:45:15] And what that does is it prevents, a more robust, if you will, target to receive the signals from the transmitter. so that's the purpose of satellite. And a lot of these newer receivers, you can plug, I think three, there's some of them, you can plug three satellite receivers. So if you've got a really big airplane or sailplanes, especially, really high performance sailplanes, the fuselages sometimes are made of carbon fiber.

[00:45:43] And carbon fiber is not a very good, it's, it's, it, I mean, it, it blocks.

[00:45:48] It'll block.

[00:45:49] Yeah. Yeah. So it's important, especially on airplanes like that, to use these satellites, strategically to, to try to get a good signal to your main receiver. And, and that's the function of a satellite.

[00:46:01] My Yak has two of them.

[00:46:03] Yeah. My, my old, Hangar 9 Yak here, I've got two satellites in that as well, in addition to the main receiver. more, right.

[00:46:12] And, and more is better.

[00:46:15] It will.

[00:46:15] Yeah. And the nice, nice thing about those two is, you can, you can put a nice long lead on them.

[00:46:20] Right.

[00:46:21] And get them far away.

[00:46:22] Yep.

[00:46:22] If you have a bigger airplane, especially get that as far away as you can, don't just put it right next to that other receiver six inches away.

[00:46:30] Exactly.

[00:46:31] I, I think I have one on a, a five foot, extension and get that like back in the tail section, get that as far back as you can.

[00:46:41] Yep. Yeah. I've got it. I've got it mounted in the turtle deck of my Yak.

[00:46:45] Yeah. Right. And, and the nice thing about that too, is that kind of helps prevent some noise, especially if you have a gas engine, those, those ignitions create a lot of electronic interference and a lot of noise. so by getting that as far away as you can, that helps too.

[00:47:00] Right. Yep. Yep. So that's the, that's the function of a satellite, receiver is just, it's just to augment the, the site picture, if you will, of your main receiver to get a better signal, from the transmitter, just to help guarantee that you don't get those brownouts or signal.

[00:47:20] Well, yeah, I was going to say, it doesn't necessarily have anything to do with brownouts because they don't, they don't, yeah, they don't handle that. They don't handle any, any electronic, I shouldn't say it. They don't handle any, servos or anything like that. there's nothing else plugged into them. They are simply, simply antennas.

[00:47:38] Yep.

[00:47:38] The, the, yeah, they just give you a better signal, into the airplane so you can see it better. not see it, see it, but so your, your receiver can talk to it, your transmitter better.

[00:47:51] Yep.

[00:47:51] So.

[00:47:52] Yep. That's right.

[00:47:53] Anything else you want to cover on this one?

[00:47:55] I don't know. I, I kinda, I kinda think I'd, I'd like to talk just briefly, about the, the serial or the, or the S bus type receivers. I mean, just.

[00:48:07] I, I don't know anything about those. So, yeah.

[00:48:10] And I, and I, and I don't know very much about them. aside from, the, the, FPV and drone guys use them, because especially on these small racing drones, they don't have a lot of area.

[00:48:26] Now you yelled at me for talking about drones before, so now you're going to go ahead and do it.

[00:48:30] Well, I'm just, that's where the application really lies with, with these receivers. okay. And the only reason I mentioned is because, if, if buying a receiver is in your future, this might be one you can sort of take off of your radar because for, for standard model airplane use, we don't generally use those S bus or, PPL type receivers because they're really designed, not for airplanes. They're designed for drones and things like that.

[00:49:02] So, like I said, if, if you're in the market for a receiver, that's one option you can sort of take off your list and try to help clear up the, clear up the choices, just because they, they're really not designed for, for standard RC plane type use with the servos and all that. That's really all I wanted to say about that.

[00:49:24] Okay. Well, that's good to know. So, yeah, I guess if I see those out, I'll just walk by them. And then ignore them and not do anything with them.

[00:49:32] I mean, they, they do, they do have their, they do have their use and, and, they're pretty neat and slick what they can do. But, unfortunately they're, they're not quite, what we are, are using with the RC airplanes. And besides that, I mean, we have other means we can use that, that they really clean up installations, because you're only using one wire from the receiver to drive all these different motors in the case of, drones.

[00:50:00] But, we talked about the smart trays and that's kind of the same idea sort of, and that's what we use to clean up the, the mess in the big airplanes. So anyway, stay away from those receivers. You don't need them.

[00:50:14] Good advice. Leave them, leave them alone.

[00:50:16] And they're expensive anyway. So there.

[00:50:18] Oh yeah. Save some money then. Buy a, a higher channel receiver.

[00:50:22] There you go. See, buy more than you need. It always comes back to that. Yeah.

[00:50:27] There you go.

[00:50:28] Yeah.

[00:50:28] Okay. Well then I think for me, I'm done. If you're finished, then, we'll sign off until next time. I'm Ron.

[00:50:35] I'm Tom.

[00:50:36] See you later. Bye.

[00:50:38] We hope you enjoyed this episode of the RC plane lab podcast for topic suggestions to ask questions or to give anything back, connect with us at rcplanelab.com or email us direct at either ron at rcplanelab.com or tom at rcplanelab.com. You can also text us or leave us a voicemail at 818-351-9846. Please subscribe, rate, and review us on your favorite podcast app. Until next time, may your landings be gentle.