PCM or PPM?

Unless you fly in downtown LA, I see no reason for the $$$ of PCM.

True, PCM has failsafe, but that sometimes crashes your plane. A plane can fly through intermittent interference most times. A PCM detects interference and locks the controls. This is good, unless you're in a vertical dive at the time. After the interference is gone, it takes a couple of seconds to return control to the TX. That might be a couple of seconds too long.

I've flown PPM over 15 years, and never lost a plane to interference. Dr.1 Driver "There's a Hun in the sun!"

Do a search using those terms on

and you'll get a ton of opinions. Everything that can be said about the subject HAS been said about the subject over there so there's no reason to start the argument all over again here.

MJC

Apologies, I wasn't trying to start an argument! My son has just built a P51 Mustang and took it to the local shop for checking. The shop owner swapped his PCM receiver for a PPM receiver saying that as he had a 4 stroke engine, PPM would be better due to the increased 'noise' from the 4 stroke. So did he get a good deal or was he duped?? The swap was free BTW but should he get his PCM back?

TIA

cheers, Len

Wow, first I've heard of that. Did the hobby shop guy also refund the difference in price for a PPM vs. a PCM receiver? The PCM receivers are quite a bit more money. If the guy did a "free" swap, you were on the losing end of that deal.

D> >

Len,

This will open a big can of worms, similar to the famed "downwind turn theory".....

After a ho' buncha years in the sport, my opinion is there ain't a whole lotta difference.

Both are FM transmission and subject to the same types of interference. PCM has a failsafe position you may assign to servos, but UNLESS the interference disabling the receptionsubsides in time, the best PCM will do over PPM is give you a few more seconds to get the broom out......

Cheers,

Thanks for the advice. Methinks he'll be taking it back for a re-swap! The problem is that he's going to fit a HAL 2100 unit and therefore needs a failsafe on the throttle (at least!) and if he keeps the PPM then he's going to have to buy one!!

cheers, Len

That is sort of like asking "Is you a Found On The Roadside Dead" man or Chevy dude? They both have their place and both have good and bad things that can be said about them. You pay your money, take your chances.

The PCM stuff is somewhat more expensive and SOME claim not really good on gasoline powered birds. As others have suggested, do some reading.

I think you got screwed. PCM receivers are more expensive than PPM. If the guy told you PPM was better than PCM, he flat lied to you. As far as which is better, opinions abound. Some guys swear by, and some guys swear at PCM. Personally, all of my giant scale planes get PCM. I regularly use both with no problems. IMHO. (I think your LHS took advantage of you, though) Bill

I doubt it........not here.

yep, here we go again. And you will not receive an answer that will help you. I promise.

Don't overlook the fact that the new generation of PPM receivers are now employing FailSafe too. There is now no longer any advantage of one mode over another other than that the PPM receivers are less expensive while offering the same performance.

MJC

Your local hobby shop stuck it to you, regardless of which is "better". They probably took your R138DF receiver worth $ 119.99 and gave you an R127DF worth $64.99 . Take a Tower add with you or print out from their web page and have a talk with your local hobby shop crook. Increased noise from a glo four stroke over a glo two stroke? Again he was wetting down your leg.

Red S.

should > >he get his PCM back?

How long is that proverbial piece of string? You need to understand the pros and cons of both to decide which is best suited to your particular purpose.

As for meaningful answers. Unless you're trolling you'll largely receive the same sort of uselessly emotive answers one does when asking "Which is better": (a) 4 stroke or 2 stroke?; (b) castor or synthetic?; (c) mode 1 or mode 2?;

:)

Wow! What a ripoff! Who was this "Hobby shop"?

RPM.

Neither. Both can me made to work well, and both can be implmented in a shoddy way.

Which is better - V8 pushrod or turbo charged 4 cylinder with overhead cam?

(d) a an F16 or a bicycle?

(answer a bicycle, becasue you can strap it to the back of your SUV). :-)

Goedendag Len ;-)

| ... Apologies, I wasn't trying to start an argument! My son has just | built a P51 Mustang and took it to the local shop for checking ... Just to be on the safe side, I assume/hope the Mustang is not your son's first model? (Cause you're asking here on his behalf)

Met vriendelijke groet ;-) Ron van Sommeren near Nijmegen, the Netherlands

Last summer I mounted a digital camera on my LT-40 with Hitec PPM and took to the air. After flying about 500 feet from the strip I gave it left stick to bring it back but the plane took 30 seconds to complete its 180 i.e. I had to hold full left stick for 30 seconds to make the turn. As it turned out the camera was generating noise on the receiver's power line and the control surfaces where flapping like a galloping ghost system as soon as the ship put a few hundred feet between it and the transmitter. Just like a galloping ghost system the flapping control surfaces averaged their flap in one direction or the other depending on stick position. This allowed me to get the ship back to the strip safely (and fix the camera problem) but I wonder if it was a PCM system would the controls have locked out and cause my ship to sail off to uncharted waters?

PCM