do i need a pcm receiver with gas?
 

hello to all just wondering here i am about to get my first gasoline powered plane and will be using my futaba 6exa super radio. do i need a pcm receiver or can i use the one that came with my radio? the motor is a brison 69cc in the new lanier yak 54 if this makes any difference. it seems a shame to spend another $100 dollars for a pcm if i don't need it. thanks

RE: do i need a pcm receiver with gas?
 

PPM will work fine... I prefer PCM, but the PPM will work fine

RE: do i need a pcm receiver with gas?
 

I know that PCM is no silver bullet, but anything that gives me even the slightest edge is worth it. I don't mean that you go overboard in expense, but some common sense can save your plane and possibly avoid injury.

I also only used PPM for many years, with good results. A single incedent with a "wild" plane made me change my thinking. Fail-safe alone is compelling. I know there are non-PCM RX's with fail-safe, so take your pick and make your choice.

This sport/hobby/obsession is great - we can make choices.

Safe Flying!

RE: do i need a pcm receiver with gas?
 

You do not need PCM. PPm works just fine. If you should decide to use PCM, set it up with a PPM first and make sure you have no "glitches". If you do, PCM will hide them, and make you think the problem is gone, that is, until it locks out in PCM.

RE: do i need a pcm receiver with gas?
 

Well you don't HAVE to use a PCM receiver. You can set the plane up using your PPM receiver and work out all the bugs with that. But, chances are you are going to have trouble getting a decent range check with the PPM with the motor running. THEN is when you will decide you better try a PCM receiver. I tried to get perfection with my PPM receiver and couldn't do it. So I switched to PCM. It's what the experts fly, so its good enough for me too. Good luck and keep us posted on how the range checks go...

Bob
Dynaflite Super Decathlon...US41 engine...18x6-10 Top Flite prop....Futaba PCM....awesome!!!!:D

RE: do i need a pcm receiver with gas?
 

NOT True. I do not own any PCM receivers and many of my aircraft are gas. If you set up right you will not have RF issues.

RE: do i need a pcm receiver with gas?
 

Well, just because one guy in ten gets a good range check with PPM doesn't mean we all will. Like they say....no two airplanes are alike. I'd keep a PCM receiver handy just in case. Its what PCM was invented for....it has failsage features and superior noise rejection. IMO

Bob

RE: do i need a pcm receiver with gas?
 

Bob, you may want to search around on the boards and make sure you know what you are talking about. It is generally accepted that hiding a problem with PCM is a bad move. The majority of pilots using PCM, at least those whose post on RCU, make absolutely sure they have no problems with PPM befor using PCM.

RE: do i need a pcm receiver with gas?
 

I also fly PPM (actually I use Multiplex IPD RXs with a JR TX). I get the benefits of failsafe setting with the advantage that I will know that something is going wrong before the plane completely locks out on me. I don't use IPD because they are cheap (they are not that cheap), I use them because it's what I like in my 35% IMAC planes.

I get range checks with the engine running that are so good I get sick of walking. They are as good as engine off. I do engine running range check before the first flight every day I fly, just to check for changes.

Even if you set a bird up with a PPM then huck in a PCM, things change over time. Ignition shielding breaks down, connections come loose (of course, I solder everything and don't use servo extensions), etc... With PCM you won't know until you lock out... then you are hosed.

The EXPERTS are usually sponsored and use what is given to them by their radio sponsors... I'm not saying they wouldn't use them anyway, but it is not a fair comparison. I know a guy that is sponsored by a radio company and he hates it, but he keeps using it to get cheap servos, RXs, and TXs. Take what you can get I guess.

RE: do i need a pcm receiver with gas?
 

I love the "PCM hides problems" idea. Sometimes it takes me a long time to stop laughing. PCM does not "hide" problems. PCM does not recognize it as a problem and therefore it DOES NOT EXIST to that system. If it doesn't see it, then by definition it is NOT a problem.

A good example are my two cars. Side by side in the driveway my truck, which usually works fine, gets terrible reception while my wife's car brings in the same station 5 by 5. So I guess her radio is terrible since it is "hiding" the interference that my truck is picking up. We have high tension wires behind the house that cause this interference.

But put that argument aside for now. I prefer PCM in anything I fly because I can get a predictable result in the event of interference. In other words, rather than wild uncontrolled glitches that may make the plane do something very bad, I can program what WILL happen. Now that may not save the plane, but I know 100% I've been hit and the plane is doing something predictable rather than not.

RE: do i need a pcm receiver with gas?
 

Easy way to find out,,do a poll planes lost to PPM verses PCM,,see what you find out,,,,,PCM all the way here,,,especially in large gassers..and yes ive used both,,

NdFrSpeed

RE: do i need a pcm receiver with gas?
 

Well then...what do you suppose they created PCM receivers for?? Just for fun??? I've looked around the forums and it appears to me that PCM is a great tool for solving otherwise impossible problems. Sooner or later your gasser will start creating RF noises as thing wear and ignitions get old. PCM is cheap insurance that my plane always returns from it latest mission.

I remember years ago we had this same discussion when they came out with Dual Conversion receivers. Many people believed it was over kill. Too technical....too much chance of failure due to a higher parts count. Whew.....Those same people can't live without dual conversion today. Singel conversion works....but your living on the edge.

Using the logic that PCM only masks the problem....maybe we should all go back to regular spark plugs because resistor plugs only masks the problem? Whew....

PPM works....but your living on the edge. IMO...:D

Bob