Infinite reduction.

What do I have to divide a number by to make the result 0?

I have to come back to this. Been at the back of my mind for a while and a recent posting on BOPL triggered it.

Matt I don't think you or anyone else should be flying a partially guided missile anywhere close to the general public. I can't go to the extreme and say you can not fly at all. However I will say that you need to find some section of Area 51 and fly there. If anyone want's to come and watch then they have signed off on the potential harm that might come their way.

Now don't get me wrong I just may be one of the spectators or if I win the lottery a builder flyer. However I sure will take the maximum precautions.

So this answers your roll rate and signal fading and other problems you have created by competing with air to air and air to ground missiles. For the rest of us poorer modelers spread spectrum would be more than fast enough.

Would also take away the AMA's Reason For Being Number Two -- Save The Frequencies!

SoCal GliderGuider

This looks an awful lot like the pot calling the kettle black. Of all the groups I have been involved in, the sailplane pilots break the rules more often than any other. It starts with launching and flying over houses, exceeding the 400 ft altitude limit near airports, flying over the pits, flying behind the pits, landing behind the flight line, and on and on.

I have several friends that are into extreme soaring and fly considerably in excess of the posted AMA speed limit for turbines. Having callers on the line hiding behind boiler plate is not exactly amoung the safer things what we do as modelers.

Why rag on one of the very few people that have actually built and do fly spread spectrum? Why rag on any area of modeling? We are all in this together.

Reducing spread spectrum to the use of only thremal sailplanes will increase the price, do to lack of demand... not decrease it. The demand for the first units of any technology has always been at the top end of the market and then there is a trickle down affect. The guys that want a spread spectrum unit NOW are willing to pay the piper. Sooner or later, it is likely that we will all have it. If you want it NOW, open your wallet and start dumping out the cash.

I suppose that the AMA does watch the FCC fairly closely, along with the FAA, OHS, and other agnecies. I am not aware of the AMA making a major deal about any of it unless there is some percieved threat. If you don't want to be an AMA member, it is not a requirement. If, on the other hand, you want to fly at a site, or at sanctioned events where the members of a club have chosen to charter with the AMA, you have no choice. That is your decision and the decision of the club. There is at least one member of this forum that chooses to go to the hi desert here in So Calif and fly a turbine without an AMA membership. There is certainly no reason that you can not do the same, if you so choose.

http://www.modelavionics.com/WiFLi/default.asp

it appears that the pudding is nearer to being proofed that some would believve.

UGH I am not sure why I keep doing this.....this forum is becoming absolutely ponderous.

I did_not_say we were flying at 300 mph. When you design things, you need DESIGN margin. Our potential customers are jet pilots. They regularly fly at 200 MPH, maybe a little above that in the real world, under complete AMA sanction and while enjoying full AMA coverage.

700 degree per second roll rates are not excessive, I don't think the AMA has any rules on rolls rates (yet). So mayking sure your design will work when the antennas are flying around at 300 MPH, 2000 feet away from the transmitter, with the plane rolling at 700 degrees per second is a pretty reasonable design specification. We have been flying it in a pretty benign environment, a trainer if you must know.

We have been running spread spectrum in one form or another now for years. And for years we have seen people pipe up about how easy it is. All I am saying, is in a jet, it is not that easy. If you are doing RC cars or maybe battlebots it is not too hard.

We have briefed the AMA on one potential system. We have flown it many times. Obviously others are working on it. We don't say too much as we have intellectual property wrapped up in it.

I just read some of the recent posts and I feel I must bring this out again:

Everyone should think long and hard before writing off our 72 MHz frequency allocation. Path loss is proportional to 1/(frequency squared). At 2.4 GHz we would have about 1000 times the path loss we have at 72 MHz. Saying this in another way, a 2.4 GHz transmitter would need to transmit 1000 watts to produce the same voltage across a receive antenna as a 72 MHz transmitter transmitting 1 watt. This is basic physics and there is nothing we can do or ever will do to change it. Remember, we are using omnidirectional receiveing antennas and as frequency goes up the effective aperture of the antenna must go down.

Sure, 2.4 GHz spread spectrum has advantages in preventing fading and some processing gain and some reduction in atmospheric noise, but we have a large initial disadvantage to overcome. I'm not sure that we will see a 2.4 GHz spread system that offers the range and robust signal quailty that we get from our 72 MHz systems.

Shown one system? Intellectual property?

So this is a business thing. What gave me the impression you were doing this for the AMA membership and the US modelers at large.

Sure hope it was not implied from anything I posted suggesting that you contact Matt and then plan on opening your wallet. Maybe you thought I was kidding about getting on the list and planning to spend plenty.

If so, let me make it perfectly clear: I was not kidding.

scgg,
now you just sound like a troll.

I give up, what gave you that impression?

Well, the absolutely the path loss is very high, but the bandwith is also very high. We have 100 times the bandwidth of the 72 Mhz systems. So on 200 mW of power, we get 1-2 miles of range, if the antennas are optimized.

I have nothing against 72, there are just too many people on it now to afford to fly expensive planes on it.

FCC gives spread spectrun 900 mhz and 2.4 ghz end users 1 watt with out having to license. At least 3 miles of range optomized or not.

Point the antennas at each other and tell me your range. Have one antenna pointing horizontally and one vertically and tell me your range.


Range has many factors.

Transmitter Power

Transmitter Antenna Gain/Polarity (in the direction of the RX)

Path Loss (as stated here, very high at high frequencies)

Receiver Antenna Gain/Polarity (in the DIRECTION of the Transmitter )

Receiver Sensitivity


Here is Gen II (second flyable prototype transmitter)

I'm buying one of these and the rest of you can just be cry babies.

http://www.modelavionics.com/WiFLi/default.asp

or

http://www.auav.net/products/spread-spectrum/index.html


Finally the end of the AMA Frequency Crusades! Or AMA's Reason For Being Number Two.

Alunimun Beanie's anyone?

I looked at the 'pictures' and reviewed the site and wonder exactly what the intent really is. The STATED intent is to make sure that "the aircraft will be completely autonomous". Those are not my words, but those found here:

http://www.auav.net/products/spread-...ion/index.html


If we are to grant that this was just the approach used in the 'test bed', then we must assume that ALL the hype about SS is strictly a financial deal to make a few greedy radio manufactures richer at the expense of the average AMA member who flies in hostile RF environments. That appears to be the only explanation for these things are being kept under wraps.

In discussion there was some concern that other countries would be unable (or is it unwilling?) to grant usage rights in the frequency bands most of the common SS applications use. Clearly that was an unfounded concern and now it is clear that the radio manufacturers are just helping themselves to modelers money. Bad attitude #76. Anyone got any better ideas?

Elementary, my dear James. When you lose the control link, the aircraft is then autonomous.

Abel

ROFLOL!

Since that is a violation of the Safety Code, wouldn't it mean you are no longer insured? Hmmm.. That is what we have with PCM systems today, so the question is important NOW. GREAT radio systems we have, just great.



(scrambling for my flame suit!)

Now tell us about the other link. I posted two knowing full well what each implied. Interesting you want to honk your horn about the autonomous site. Still it has a technical page that does a decent job of describing SS.

http://www.modelavionics.com/WiFLi/default.asp

You can use that system on your Extreme Aircraft Yak with a BME 55. I wish I had a nickle for every manufacturer that announced a product and was never able to deliver. I hope they are successful but I won't hold my breath.

Almost as interesting as the observation that you would rather launch a personal attack than discuss the subject.

You posted the other link a week or more ago, here or on R/C Groups, and I have been watching. Do you really want to use that as the basis of a discussion when it is NOT available? Pretty boxes do not prove any system, which most serious vendors of techinical products understand. Have you ever heard the term "Vaporware"?

What do these statements mean? Do you think SS is just hype and is not needed? Sorry I do not understand...what is "under wraps"? THe initiative I know about are all out there on the web as far as I can tell...

Matt,
You guys seem to have confused some general observations and thoughts with personal attacks. Please back off and don't do that because it gets in the way of discussion.

You and your 'competitor' both posted nice pictures. He has taken the extra steps to post more than one makers detailed commentary about their products. Bully for him, but I have some serious questions. As you, and others, have noted much of what is seen on the web is bogus. One of his sites speaks of being 'available' in JULY and the other talks about flying autonomously, which is against the rules. You have been keeping your availabilities, functionalities and the like under wraps for what is probably good reason; which is why I opined about the few radio manufacturers.

Lets look at it slightly differently. I have a significant investment in my present radio systems and am unwilling to throw them away for something new, neat and tricky, and unproven from an unknown maker. My negative opinion about radio makers is/was directed to those who make the systems I currently fly as it is fairly clear that it did not take millions of dollars for you and others to create an effective SS based system. I want an effective SS based system, but am unwilling to mortgage my first born male child to buy one from a restricted specialty source. In other words, I don't want to be the only one in my club flying with that system and feel the hobby needs to move in this direction.

I hope that clears up my comments for you.

Yes it does, and I did not take it as an attack.

And just to clear up some things. The Model Avionics system is for surface use only. Planes are an entirely different animal, because of the 3d maneuverability.

The other system, well I do not know. If you only fly simple trainer type aircraft, and you are careful with your TX antenna, it might work. But not as a hobby type usage. The automous thing is a canrad, he could just leave that part out and it would be within the rules.

IMHO, the reason it has not been done by the radio manufacturers...the current stuff works OK, and a new SS radio would be very expensive to make, with a limited market. Same exact reason you do not see any mass market Asian turbines, and likely never will.

Hey Jim,
Have your turbine shot down by someone with a trainer and then tell me you wouldn't pay five times what your present radio is worth to get something that could not be shot down. Why would you seemingly oppose new technology in the hobby? Expensive innovations have a trickle down effect that eventually benifit the average modeler when the economics of scale bring the price down to what is percieved as reasonable.

Sorry James old man was not I that posted the other link over a week ago. I was just pointing out where technology is taking modeling and over taking AMA's antiquated approach to public safety. Still you wish to ignore the obvious and discredit it with out further investigation by regurgitating about the autonomous link and trashing me.