3DFanatic

My Feedback: (5)

Shame shame on yooooooou

JohnW

My Feedback: (6)

I fear that the listed unit would not be legal to operate in the US, the 2.4-2.483 is listed by the FCC for other uses. The FCC also clarly states that RC is allowed (only?) on certain freqs. However, I look forward to seeing how well it works. Spread Spec could resolve a lot of flying site issues.

Bob_Wilcox

My Feedback: (1)

Hi John:

It is FCC legal to fly on the ISM bands! That was the judgment from a FCC specialist attorney that the AMA uses. The AMA will need to accept it however.

The 900 MHz unit that I am currently using would not be legal outside of the USA. In fact, 2.4 GHz is very limited outside the US as well. I think it has a maximum of 20 dBm in many countries in Europe. From my tests, I think 100 mw on 2.4 GHz would be marginal with low gain omni directional antennas.

As a US amateur radio operator, I can transmit up to 100 watts (50 dBm) as long as it is adaptive on these bands. I don't play with the High Speed Multi-Media stuff so I don't know all the limitations other than the data would need my call sign, SSID and could not be encrypted.

mr_matt

My Feedback: (10)

The 2.4 GHz Industrial, Scientific and Medical Band (ISM) is available for any use imaginable, that is not malicious in nature (ie I cannot make an ISM jammer for instance). All other uses, including RC are fine. THere is nothing in the regulations that LIMITS RC to the 72 Mhz band, although the CFRs definitely set up the 72 MHz band with RC as the exclusive users.


We suspected this 3 years ago when we started talking about this. We went to the AMA and they agreed.

Sport_Pilot

I have to wonder if many people would buy such as system. No doubt most of the large planes and jets would buy one. But would very many others pay the extra price for such a system. In almost 30 years of modeling I doubt I have experianced more than a dozen or so problems with interferance. And only a very few resulting in a crash. I bet if I had been able to get to a flyaway I would have found at least one of them to be a battery problem. Its possible others were from other problems as well.

Also I would wait till such units are in the system for a fairly long time. Not just to wait for the price to come down, but to be sure they are reliable. Hate to trade one problem for another. I wonder if the transmitter and reciever could get out of sync and be on the wrong frequencies?

Bob_Wilcox

My Feedback: (1)

Sport Pilot:

I agree! If you are flying sport planes with relatively low investment compared to big scale models, scale helicopters, IMAC planes or jets, I would keep using the current technology that is available now. It works very well!

The problem is when you are flying $7,000 - $20,000 jet models and a newbie comes to the park and accidentally turns on his radio. And it not just newbies! These mistakes have been made 3 times that I know in the last year at my field wiping out at least $20,000 worth of planes and initiating lawsuits over the crashes. At big events, there has been many errors in frequency control that has also crashed very expensive planes. When you are flying expensive planes, it does not make sense to have an RF link that is susceptible to interference or frequency control errors when there is a much better way.

Jets also require lots of channels. We just barely get by with 10. I made our system 16 channels and any channel can be mixed together without any difference in latency between them. Another words, you can mix channel 1 to channel 16 and the servos will travel precisely together. I cannot do that with my 10 channel system. Another feature, my caller can know what my engine temperature is, how much fuel is in the plane, the voltage of the batteries, airspeed, altitude, etc., etc. Flying my sport plane, I could care less about this info but with my jet, it is very valuable.

I do realize, compared to sport market, this will probably have a very limited market.

staraero

My Feedback: (1)

There is nothing more constant then change. A change has been long overdue concerning the method and freq. we use, to transmit the signal and comands to our models.

If you just simply consider the advancements other electronics have enjoyed, we are considerably behind the tech. curve with our current RC equipment.

Maybe this system will work, maybe it won't. My money is on it working perfectly. Either way, nothing is forever. The freq. and method we transmit will be subjected to this rule as well, sooner or later.

Staraero1

JNorton

My Feedback: (2)

Staraero,

"A change has been long overdue concerning the method and freq. we use, to transmit the signal and commands to our models."

Technically what you say is true, however the great inhibitor to technical advancement is our government bureaucracy and small population of RC modelers. The frequencies and methods of modulation are totally limited by FCC regulations. I for one would be extremely hesitant to try and get them to open up our present frequencies to allow spread frequency (on our current frequencies) because once the door is open we could loose what we already enjoy that works well for the majority of users.

I do see the need for a spread frequency or something like it for the mega expensive jets or scale aircraft. But given the realities of the small size market with limited financial rewards, I don't see anything like this happening soon. Unless it is through the efforts of some die-hard modelers, like Bob Wilcox and Mr Matt. Gentleman I applaud your efforts and hope you make some gold for a reward for a long and tedious job.

John

mulligan

Boy, this discussion, along with myriad specialized AMA rules for large and/or turbine RC aircraft makes me wonder if we'll eventually see a split in the hobby where the "big boys" have their own governing organization, fields, insurance, transmission parameters, etc. This seems like a natural evolution and not altogether a bad thing.

Panzlflyer

My Feedback: (15)

How is that a good thing or do you think that most people jump right into the big stuff?
Dont most people with a modicum of common sense transition thru the various sizes?
Splitting in two organizations will bring on more bureaucracy and make each sides voice smaller.
I fly the bigger stuff NOW but lets remember where we started. IMHO

mulligan

Didn't mean to start a war, Andy. But just like the US Air Force came to be out the Army, once a specialized discipline matures, it can be better to spin it off into its own entity; the benefits outweigh the added bureaucracy, etc.

And I'm not saying that's where we are. I WONDERED aloud MAYBE that's where were HEADING. I personally don't think we're there.

However, I'm sure glad we're separate from the FAA (talk about bureaucracy!). It's already been discussed in other threads that if our aircraft continue to evolve to be bigger and faster, the AMA may find it more difficult to prevent regulation from the FAA or some other intermediate level of regulation (akin to experimental class). In that hypothetical, I think a split that would separate the smaller scale aircraft would be a great benefit in allowing those flyers to avoid an increased level of regulation.

I'm sorry for dragging this thread off-topic; it wasn't my intent. I do appreciate the peek into the evolution of radio in aviation, as that's not my strength to say the least (EE was my least favorite class back in school ). I would appreciate it if anyone could give a reference for learning more about multi-spectrum or blended-spectrum transmission (I'm not even sure of the terminology). I just don't get how this sort of transmission allows multiple users without potential interference.

Panzlflyer

My Feedback: (15)

After I replied I was wondering if a Channel guard system might not help some in all newer radios. I know Multiplex has it but my high dollar 9z does not.
Also have people looked at what FMA has done with their reciever being able to recognize its own transmitter? Worth a look at their faq.

strato911

While we're talking about channel guards, and automatic receivers, let's not forget the Tracker II / Seeker radio from Polk's Hobbies. The Tracker II (Tx) has a built in scanner which scans your intended frequency for interference before it turns on the RF circuitry, and the Seeker (Rx) auto detects ANY Tx (positive or negative shift) while in programming mode. And to top it all off, it's digitally synthesized. No swapping crystals on either the Tx or the Rx, no turning of dials to change channels, no reversing switches to wear out, and stores 99 model configurations in FLASH memory (no backup battery) it's all digitally controlled.

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