haz

My Feedback: (17)

Iam going to get a new radio i have it down to 2 the futaba 8u pcm or the new futaba 9caf - fm radio. I fly helicopters and planes . should i get the pcm 8u or the new 9caf? The radio i have now is a rd6000 that i have outgrown.

HarryC

My Feedback: (1)

As long as you understand that the 9CAF FM is still an 8 channel radio, not 9 channels, get the 9C. A JR 8103 does not have 8103 channels, a Multiplex 4000 does not have 4000 channels and a Futaba 9 does not have 9 channels. It is just a name.

Harry

vanman

My Feedback: (2)

WOW, that was a little harsh! Information does not have to be given in a humiliating way. That being said, the 9CA is indeed an 8 channel radio, you have to get the 9Z to get the 9 channel.

All in all I would recommend the 9CA, it is truly a great radio.

Good luck with which ever you choose

Flyfalcons

Actually the 9Z and 9C's 9th channel are both non-proportional, if I remember correctly. The 9C has nine channels in PCM mode, using a PCM receiver. Not that it's a big deal, because the only Futaba 9 channel available is PCM. I just odn't understand why people say that a channel doesn't exist because it isn't proportional. Oh well, I'm happy with mine.

sfaust

My Feedback: (11)

Its more their marketing than anything else that gets people pissed off about the 9th channel. In every ad for the 9Z I have seen, they say "9 channels" and "1024 High Resolution" in the same breath. That is just plain misleading for most. Sure, its 9 channels. 8 channels are proportional at 1024 resolution, and 1 is proportional at 2 resolution. The fact that the 9th channel is switched is not mentioned on the package, their web site, or in their ads. When you bring it home and open the box and find out, you already own it anyway. Most hobby shops and mail order firms will not take returns on radios unless defective. Thats a very unfair time to tell them its only 8 proportional channels.

In their features chart, they list the 4V, 6V, 6X, and 8U as 4, 6 and 8 channel radios. They are all proportional channels. The 9C and 9Z are listed as 9 channels radios. One would expect that to mean the same as the 4V, 6V, 6X, and 8U, being that they are all proportional channels. There isn't even a foot note to state the difference. What if they also listed the 4V as a 4 channel, but in fact it was only 3 proportional channels with a 4th switched? Hmmm, that would never go over well.

I could hear the arguments from just about everyone if they listed 15 servos, and the torque specs. The first 12 torque specs being listed at 4.8V, but the last high torque servos being listed on 6V, showing a 20% higher torque rating due to the use of 6v packs. Thats basically what they did with the 9 channel radios.

They must have felt the heat, since on the 9C, they mention the 9th switch only restriction more often, but again easy to overlook if you are not careful in your review.

No other manufacturer that I am aware of markets their radios in this fashion. Jr sells a 10 channel radio, and all channels are proportional, and any channel at all could be used for a control surface, and not just a switched function. Same with Airtronics, and all the others. They should market it as a 8+1 to be more accurate and not misleading. But then it would be much harder to market a 8 channel against a 10 channel radio for the same money. An 8+1 turned into a 9 channel seems to sell just a bit better :greedy:

I think people bring it up often to make sure others are not mislead into thinking it has 9 proportional channels. Just a friendly buyer beware message for those unaware.

cmassa

Get the 9C. Its a great radio. If you want PCM later, just get a PCM receiver. The 9C transmitter will do both. The label on the box 9CA(P/F) just denotes what receiver it comes with. The transmitters are identical.

Chris

FLYBOY

My Feedback: (11)

Get the 9C. I got an 8U and a few months later sold it when the 9C came out. The C is 10 times the radio and way easier to program. Don't waste the time on the 8U. Don't get me wrong either. The 8U was a great radio, but what a pain to program. The 9C is easy to figure out without a book. I had to order a special book to program the 8U and I had an older model of it. The 9C is the best radio I have seen on the market yet.

HarryC

My Feedback: (1)

I don’t see what’s harsh about it. His thread title specifically asks about the 9 channels in FM (by which he means PPM), so he has been misled by Futaba into believing that he is buying a 9 channel radio, because Futaba has deliberately named it to deceive people into thinking that the 9 refers to the channels, when in fact it does not. It is just a name to differentiate it from its predecessor 8. See a recent thread on rcgroups by a very disgruntled Peter Berg of Berg receivers fame, who was deceived into buying a 9C because he needed a 9 channel specifically PPM radio. If people in the industry with technical knowledge are misled by Futaba, what hope for the rest of us? The 9C is a decent enough 8 channel radio, why does Futaba have to be dishonest about it?

H

Flyfalcons

...but it comes with an 8ch receiver, so why does it matter anyway?

In addition, if you want to use 9 channels, then you get a 9 channel receiver. Both of Futaba's nine channel receivers happen to be PCM. I don't know of any negative shift 9 channel PPM receiver on the market, so please, someone tell me what the fuss is about.

HarryC

My Feedback: (1)

FlyFalcons, as far as I am aware your comment only applies in 2 or 3 countries. In the rest of the world we do have 9 channel PPM Rx that work with Futaba. The fuss is about people who have bought what they have been lead to believe is a 9 channel Tx, the shop did not tell them it is an 8 channel Tx, the box does not make clear it is an 8 channel Tx. Some like Peter Berg bought it to use in setting up and testing a 9 channel Rx design.

H

sfaust

My Feedback: (11)

You still don't get a 9th proportional channel, even with PCM, so it does matter to those that bought the Futabas marketing literature that says "9 channel Transmitter", "1024 High Resolution", and never mentions the small fact that only 8 of those channels can be used for their intended purposes, controlling the airplanes control surfaces.

Would it matter to most if they bought a car with a 4 speed manual transmission, then when they took delivery found out that contrary to the rest of the industry, Ford decided that 4 speeds meant 3 forward and 1 reverse? That is what Futaba has done, and that's what all the fuss is about.

Every radio on the market is marketed by the number of fully proportional channels it has, with the exception of the Futaba 9 series. Yet, Futaba has felt its not important to make such an important change aware to the buying public. Its not the fact that they used '9" in the nae, but that they explicitly state "9 Channels" and "1024 High Resolution" in the same breath, and even hundreds of breaths later, still never said, "9th channel is on/off only, no mixing, no assignments, no expo, no atv's, no dual rates, no nothing". The few times they do mention it, its buried.

Guys, we bought a "4 speed automatic" as advertised, and got a three speed with reverse, and no return policy. We own it. And that is what all the fuss is about. Its an awesome 8 channel radio, but its a terrible 9 channel.

For those that think its silly, wait till they open their 4 channel radio for their new bird, and find out Futaba decided that 4 channels to them means 3 proportional and 1 on/off switch. After all, it worked on the 9 series buyers, so why not extend the concept!!!

-------------------------------------------
Find Waldo. Here is their 9Z marketing page, as well as their in-depth technical comparison page. Try to the statement that says the 9th channel on the 9Z or 9C is a switch only.

Here is their 9Z page.
http://www.futaba-rc.com/radios/futj9000.html

This is the detailed specifications and comparison page.
http://www.futaba-rc.com/radios/feature-compare.html

sfaust

My Feedback: (11)

Harry,

Does the 9th channel on the non-US PPM work proportionally, or just the same as the on/off switch on the 9 channel US PCM receivers? I'm guessing its still on/off since there probably isn't anything in the transmitter to support proportional control of that channel. But figured I should ask and not assume.

HarryC

My Feedback: (1)

Stephen, I was countering Flyfalcons fair point that since Futaba only make a max 8 channel PPM Rx the lack of 9th channel in PPM makes no difference to the 9C Tx - but that only applies in N America, because everywhere else we can buy 9 to 12 channel Rx that are Futaba compatible and therefore could be misled into buying a 9C, or indeed a 9Z, with the full expectation of using 9 channels in PPM.

I am going to come to America the land of opportunity and make my fortune. Now that so many people on this forum have defended Futaba's "9th channel" as being a valid channel, I will sell 6 channel sets and when you get home and open the box you will find only 6 switches on the Tx. No sticks, no sliders, no knobs, just 6 switches. And those who defended Futaba's "9th channel" as being a real channel can not complain! I will be rich very soon. In the early 1970s in Britain, MacGregor made a radio that had a single axis stick for one servo and a pushbutton for an escapement. An escapement allows 3 positions which is more than Futaba's "9th channel"! Even then 30 years ago Macgregor did not have the brass balls to call it a 2 channel radio, they called it a 1+1.

If Futaba's 8 channel in PPM and 8 channels plus a 2 position thingy (1 less position than a rubber band powered escapement!) but only in PCM, can be called 9 channels, how many channels does a Mpx 3030 or Graupner MC20 or Robbe FC18 or Mpx Royal Evo9 have?

The Futaba 9C, or Field Force 9 as it is called here, is a decent enough radio, it can sell on its own merits as an 8 channel radio. why does Futaba need to pretend it is something that it is not?

Harry

sfaust

My Feedback: (11)

I understand the thrust of what you were saying to FlyFlacon, and was just trying to clarify something in my own mind. I'm not sure you addressed it, or I just missed it.

I was asking if the non-US 9 and 12 channel Futaba compatible receivers that you referred to could make use of the 9th channel as a proportional channel. My belief is this, and maybe you can confirm this since I am not familiar with the non-US PPM receivers you mention.

The Futaba PCM 9 channel receivers will only give the user the ability to control the 9th channel as an on/of switch.

The Futaba PPM receivers available in the US are only 8 channel receivers, and make no use of the 9th channel at all.

The non-Futaba 9 and 12 channel receivers you referenced can make use of the 9th channel even though they are not PCM, which is what you were addressing with FlyFalcon.

The point I am unclear of is whether or not the non-Futaba 9 and 12 channel radios you refer to can use the 9th channel as anything other than a on/off switch.

I believe that no matter what receiver you use, the most you will get is a 9th on/off switch. PCM. PPM. IPD. etc.

HarryC

My Feedback: (1)

Stephen, sorry I didn’t make it clear. Using a 9 channel PPM Rx with a Futaba 9C, it still only has 8 channels, we can’t get a 9th channel switched or otherwise out of the 9C Tx in PPM. Flyfalcons was inferring that because you can not get a 9 channel PPM Rx it is pointless debating the lack of 9th channel in the Tx. My point is we do have 9 channel PPM Rx so it is very valid as to whether or not the 9C has a 9th channel in PPM. I own and use a 9 channel PPM Rx with built-in programmable failsafe, the 9C works with that Rx except it only uses 8 of the 9 possible channels.

Since PCM is a proprietary system only a Futaba 9PCM Rx can be used and then the 9C is an 8+1 no matter which country you are in.

My Mpx does 9 or 12 channel transmission modes in PPM, all channels are proportional. I can use all 9 or all 12 channels to control servos that are connected to the primary flight control surfaces. Each one of the 12 channels is independently controlled for its centre, travel and 13 point curve, there is no restriction at all, channel 12 has exactly the same and all the control parameters that channel 1 has. Being PPM it enforces the rule that all channels are of equal resolution (as much as PPM can have a resolution) and of equal transmission priority, unlike the reduced resolution and reduced transmission priority of JR PCM10’s 9th and 10th channels. So even JR only offers 8 channels that can be connected to primary flight control surfaces. The Multiplex 12 channel transmission mode shifts the servo data pulse centre to a shorter time than the 1.5ms standard thus effectively shortening the total time for each data pulse, then expands it again in the 12 channel Rx so that it gets more pulses squeezed into the same transmission time frame and keeps up the refresh rate. I don’t know what Graupner and Robbe do for 12 channels.

H

sfaust

My Feedback: (11)

Thanks Harry, thats what I wanted to understand.

HarryC

My Feedback: (1)

Incidentally, you can get another 6 "channels" on Mpx by time sharing 2 existing channels. It's an add-on called a MultiNaut unit fitted to the Tx and Rx, really meant for nautical and ground vehicles. Each control gets to use every third data pulse on that channel, so 2 channels can be used for 6 separate controls and 6 separate servos/switches. But obviously the refresh rate for those controls goes from 50Hz down to 50/3Hz, fine for switching of retracts, lights, smoke, water hoses, firing guns, etc. Mpx does not claim these as channels even though they are indepedent controls.

Harry

stikpilot

wow! who is going to use 9 channels anyway???

bluesky123

My Feedback: (2)

Isn't it true that PPM protocol is limited to only 8 channels? You just can't have more than 8 channels (no matter proportional or discrete) using PPM encoding as the frame length is fixed 22.5ms.

In order to squeeze more channels into Pulse Position Modulation packet, Multiplex "enhanced" PPM standard and developed a proprietory Intelligent Pulse Decoding protocol.

There's some good info on PPM vs. PCM:
http://www.aerodesign.de/peter/2000/...M_PPM_eng.html

as well as some more on different encoding standards (in Russian):
http://www.rcdesign.ru/rus/articles/radio/ppm_pcm/

sfaust

My Feedback: (11)

You would be surprised at how easy it is to use up 9 channels when you're airplane using 10 to 14 servos. You know all those big aerobatic and scale airplanes you see. They are the ones using up all the channels. Add in the Jet jockeys, scale pilots, and there are lots of people using 8 to 10 channels regularly.

Here is a typical example in a turbine jet;
Right aileron
Left aileron
Elevators
Rudder and Gyro
Gryo aux channel
Turbine ECU channel
Turbine aux channel
Nose gear steering
Retracts
Smoke pump/controller
Flaps

My typical giant aerobatic planes;
Right aileron
Left aileron
Right elevator
Left elevator
Rudder (3 or 4 servos ganged)
Throttle
Choke servo
Smoke pump
Ignition on-board kill

For scale airplanes,
Right Aileron
Left Aileron
Elevators
Rudder
Throttle
Retracts
Flaps
Lights
Misc scale features

stikpilot

YOU KNOW I FORGOT ABOUT JETS AND GIANT SCALE. NOW I SEE WHERE NINE CHANNELS MIGHT NOT BE ENOUGH. PBF'S HAS GONE TO MY HEAD AND IT'S HARD TO THINK

sfaust

My Feedback: (11)

I have blinders that automatically come on at times myself. I have to keep reminding myself that when someone asks a question that I try to answer, that they are not flying jets or big aerobatic airplanes. Otherwise, I make incorrect assumptions, and get some funny looks when they read my reply

HarryC

My Feedback: (1)

No to both! There is no standard that PPM must be a fixed 22.5ms frame length. The PPM standard is simply that the sequence starts with a synchro pulse of 2ms OFF, or at least 2ms OFF, then read each servo's data in sequence separated by a tiny OFF, until receiving another synchro pulse. That synchro pulse might come after just two servo's data in the case of a 2 channel car transmitter, but will still work even with an Mpx 12 channel Rx because as soon as the Rx sees a synchro pulse it goes back to the start regardless of how many servo pulses it saw. On the other hand a 4 channel Rx can read a 12 channel Tx because it just ignores everything after servo 4 until it gets the synchro pulse and starts again.

Furthermore the PPM "standard" is not for a servo pulse of 1 to 2ms centred at 1.5ms! Mpx uses a centre of 1.6ms compared to the Japanese 1.5ms, JR uses a pulse length +/- 0.4ms, Futaba uses +/- 0.43ms, and Mpx uses +/-0.55ms. So an Mpx pulse is from 1.05ms to 2.15ms, a JR pulse is 1.1ms to 1.9ms and Futaba 1.07 to 1.93ms. Yet they all work together perfectly well because all the Rx looks for is that synchro pulse. Clearly those different values all affect the potential length of the data frame. Funnily enough they all come together at max travel, Mpx max travel is 109%, Futaba is 140% and JR is 150%, so they all meet at 2.1ms when the Mpx is used at its "uni" centre setting.

Mpx did not enhance the PPM standard, and IPD is not involved in getting more than 8 channels into the frame. It is realistic to get 9 channels into approx 50Hz refresh rate. To get 12 channels you either accept a lower refresh rate or speed up the data. What Mpx does is drop the centre to 1.4ms whilst keeping the +/- value the same, that shortens each servo's data by 0.2ms from Mpx standard or 0.1ms by Japanese standard, thus shortening the entire frame by 2.4ms or 1.2ms. The 12 channel Rx expands the data again by altering the centre back to the norm so that each servo sees no alteration to the centre signal.

IPD is available in 7, 9 and 12 channel, and Mpx has been making 12 channel Tx and Rx for years, long before it came up with IPD. IPD is basically a way of having error detection and programmable failsafe in PPM radios, it has nothing to do with the transmitted PPM data itself.

Harry

dirtybird

My Feedback: (5)

6 channel radios I am familiar with have the 5 channel installed on a switch. If its not a computer radio there is no way to change that unless you want to butcher the TX. Thus channel five is switchable only.
Nobody refers to this radio as a five channel radio.
I think the Futaba 9C is a nine channel radio.

sfaust

My Feedback: (11)

Which 6 channel radios are you referring to? I'm not familiar with any with a switch channel, but that doesn't mean I know them all. So I am curious, and want to update my internal memory database