awnichy

Hi, I was reading through the forum because I'm fixing to buy another radio. I'm an old rc'er and never really thought about these new computer radios. I have read about the 9cap and I like everything about it but I have a question, first, what is pcm and why would I prefer it over the other kind and second, I have about 6 receivers that I have been using with my Futaba 6 and more recently I bought a Super 7uaf and they all work with it. Somebody told me that they wouldn't work with the 7uap and I was wondering if they would work with the 9cap. Any help would be much appreciated.

Lynx

I personally don't see a real advantage with PCM but some people do. It's digital as opposed to analog way for the xmitter to send data to the receiver. It allows some error checking so instead of the glitches you see with regular PPM it filters it rejects signals it things are 'bad' So instead of the glitches you get 'null' spots in where you don't have fluid control of the plane. The big downfall of PCM is you don't notice it glitching before it goes completly wacko, so where with PPM you may notice you're getting interference because your servo's are twitching with PCM you won't and you might not notice it at all untill you relize you have no control over the plane at all. It also allows for setting the servo's at some preset spot in case you do lose control. untill you regain it.

Steve Lewin

Your receivers will work with the 9C Tx which can be swiched into PPM mode.

As for PCM vs PPM I'm not getting into that. It has already been debated to death many times. Try a search.

Steve

transmission_dr

My Feedback: (1)

Hi,

If your receivers are FM, they should work fine withe the 9cap as long as you select PPM modulation.

As has been mentioned the PCM/PPM discussion is an endless one.

If you have a question as to which is better, just look at what all
the big guys are using (the Chip Hydes, etc). As far as I know ALL of them use PCM.

Nuff said,

Jerry

SMALLFLY-

My Feedback: (19)

the big guys are GIVEN there pcm rx's by there sponsors.
If you list the model #'s of what rx's you have you could make sure.
But like above as long as they are non pcm futaba or hitec rx's you should be fine

MO_Radio_Tech

The contest flyers fly PCM by choice, as do most of contest Helicopter folks and Jet flying folks.

strato911

Excuse my ignorance for not knowing who Tom Hunt and Bob Aberle are, but according to Lewis Polk (from Polk's Hobbies), they use the Tracker II exclusively. This is a PPM only radio.

Al - As long as none of your receivers are PCM, they should all work with the 9C in PPM mode.

cassidy

My Feedback: (5)

Tom Hunt is an engineer for Gruman and is one of the leading experts on electric flight. He was just inducted into the AMA hall of fame.
Bob Eberle is another of the Electric experts and he writes articles for various US magazines on electric flight and radio equipment.
Also Tom Hunt is the man behind the annual NEAT EXPO that occurs in NY State in September each year.

strato911

Thanks for the explanation.

I knew they were BIG names in the US... I just didn't know the details (notice I am from Canada). Further research also showed Bob Eberle was an integral part of the AMA getting the frequency band expanded years ago, and Tom Hunt designs RC aircraft much larger than just for electrics...

crashed2

My Feedback: (4)

This is somewhat true. What happens is, when the receiver picks up a so called glitch, the rx will sense this bad command and instead of signaling the servo with this bad command, the rx keeps the last known good command until it picks up the Tx signal again. this usually happens in an instant, but if you do set the presets, you can set it for the throttle to go down close to idol without killing the engine, so if the receiver lost the Tx signal the engine would kind of hicup, which will tell you something is wrong.

Also, most of the big guys, (larger planes, ie; 30% and larger) at least the ones I know, do fly PCM, but they also fly with two receivers, which kind of splits the controls in half, one for the left side of the plane, & one for the right side of the plane, so if something was to fail, they have more of a chance of bringing the plane safetly back to the ground.