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Futaba's answer to the Spektrum DX7!

The Futaba 6EX with FASST™ System has been announced by Futaba as their entry into the new breed of full-range r/c 2.4 Hz transmitters.

As you might expect, Futaba's new FASST (Futaba Advanced Spread Spectrum Technology) system claims to have several superior features over 'the leading competitor' - and we all know to whom they are alluding, of course!

The transmitter is a 6-channel system, and is supplied with the Futaba R606FS "all-in-one" receiver (right). Weighing just 10 grams, this receiver boasts higher sensitivity and is perfectly suitable for park flyers AND all other types of aircraft - clearly seen by Futaba as another point-scorer over the competition!

Other key features promoted by Futaba are:

Custom Futaba IC Chip. Futaba’s own custom IC chips are backed by 15 years of 2.4GHz experience in industrial R/C uses, and are “purpose-built” for R/C systems. "Some manufacturers rely on off-the-shelf IC chips, without the custom application development that only Futaba’s vast experience can provide", they say.

Easy-to-read LCD Screen

Adjustable antenna to ensure maximimum reception.

Dual Antenna Diversity enables FASST system to automatically and seamlessly select the best reception between the two antennas built into the receiver ensuring that the aircraft stays under constant control of the transmitter regardless of attitude.

Smarter failsafe setting programmed from the transmitter - no complicated set-up steps or binding plugs.

Constant shifting between frequencies. The frequency shifts every 2 milliseconds, virtually eliminating signal conficts and interruptions.

Power Down Function - allows for a reduced-power ground check for up to one minute, from up to 50+ paces away - like retracting the antenna on a conventional transmitter.

Easy Link System - -the transmitter leaves the factory programmed with a unique ID code. Once the Easy Link button is pushed, the receiver will only accept signals from that transmitter, eliminating interference. With over 134 million possible codes there
is no chance for a conflict.

Pre-Vision Packet Screening Technology - scans incoming data for potential problems and applies sophisticated error correction techniques for a solid impenetrable link with the model.

Standard Programming Features:
Trainer function - transmitter can be master or student, compatible with other Futaba systems.
Six model memory.
Servo reversing.
End point adjustment.
Airplane or heli programming.
Dual Rate /Exponential for ailerons, rudder and elevator.
Fail Safe - safety throttle setting in case of transmitter signal loss.
Battery Fail Safe - safety throttle setting in case of signal loss.
Stick Mode - Choose from Mode 1 - Mode 4.
Changeable Throttle Stick - ratchet for airplanes or smooth for helis.
Adjustable Stick Length.

Airplane Features:
Programmable Mixing (1 and 2) any two channels can be combined.
Pre-Programmed Throttle Cut for safely shutting off engine.
Wing mixing for flaperon, flap trim, V-tail and elevon.

Helicopter Functions:
Three swashplate types.
Five-Point Normal and Idle Up Throttle/Pitch Curves.
Revo, Gyro and Swash to Throttle mixing.
Swash AFR Adjustable Function Rate for use with 3S or 3E swash types

Standard package includes Futaba 6EX Transmitter, Transmitter Battery, Battery Charger, R606FS Receiver and Switch Harness.

Available in the USA from mid-March at a price of $219.99, with availability elsewhere soon to be announced.

Crystal gazing

A modelflight reader wrote to me recently to say he was about to buy another receiver and crystal for a second model (to avoid swapping over radio gear), but was a bit puzzled as to the difference between "single conversion" and "dual conversion" radio crystals. A lot of folk, comparative beginners especially, probably never realise that there are different types of crystals out there, simply because they instal whatever receiver and crystal might be provided with their initial radio gear and then - if they are lucky - move it on to successive models. A lot of us know very little about the technicalities of our radio gear, so here's a brief, non-technical, look at this crystal question.

First of all, the type of crystal you choose depends entirely on what type of receiver you are using, so the real question is what is the difference in the types of receiver. If you use a dual conversion receiver you MUST fit it with a dual conversion rx crystal, and, similarly, a single conversion receiver MUST be fitted with a single conversion rx crystal. The radio will not work if you did otherwise! It is generally considered wise that you should use the same make of crystal as your receiver, whichever type, e.g., Futaba crystal for a Futaba receiver..

A single conversion receiver is a slightly simpler device (and therefore usually less expensive) than the dual conversion receiver in the way in which it decodes the signal coming to it. For normal field flying it is perfectly adequate, but it is possible for the receiver to become 'confused' if two transmitters are being used very close to each other. It is then possible for a 'glitch' to occur resulting in intermittent loss of signal. Generally speaking it is not a problem, and some believe the problem is more theoretical than actual.

A dual conversion receiver requires a dual conversion crystal and employs two mixing processes that removes the possibility of the problem mentioned above. It is called dual conversion because it actually employs two crystals - the one you slot in to the receiver for your chosen channel and a fixed crystal within the receiver. Because dual conversion receivers are more complicated than single conversion receiver they are usually more expensive.

So your choice of crystal is dictated by your choice of receiver - and here you have a further choice between PPM (Pulse Proportional Modulation) and PCM (Pulse Coded Modulation) receivers, either single or dual conversion. Your transmitter also has to be set to whichever mode you are using.

If, like the guy who posed the question, you are wanting to set up a second model to fly from the same transmitter without changing mode settings, then you will need to ensure you choose the same type of receiver (PPM or PCM) as you have in your first model. Thus, if you are currently flying on PPM mode (which is the most common) then you must buy a PPM receiver, either single conversion or dual conversion as you may decide with the matching type of receiver crystal and the same frequency as your first model. You do not have to stick with the same conversion type but you must ensure that you have the right type of crystal and of the same frequency, of course. You do not have to change the crystal in your transmitter, which will work with either single or dual conversion receivers provided your receiver is fitted with its relevant crystal.

PCM is the more sophisticated of the two and is usually the preferred choice of helicopter pilots and others who may like to be able to set up 'fail-safe' settings on their radio (where servos can be made to switch to a pre-determined setting if the radio signal fails - such as making the throttle go back to idle, so the plane will fall out of the sky!). It is generally accepted that to drive a PCM Receiver you need a PCM transmitter of the SAME MAKE as the receiver. The reason for this is that with PCM there is not as yet a common encoding standard as there is with PPM.

Any radio can be used for either single or dual conversion receivers - the thing is, the signal to the receiver is the same but it's the receiver which sorts it out in a more or less sophisticated way depending on which type you choose. The only important thing to remember is that if you are using PCM mode, your receiver should be of the same MAKE as the transmitter.

What I have just said about the transmitter signal is the reason that there is no requirement for a special crystal in the transmitter whether you are using a single or dual conversion receiver; you just need to ensure that your receiver crystal is the right one for the type of receiver you select. Make sure, then, when you buy your crystal that it is the right make and right frequency and that it is a receiver crystal -

Where's the latest issue?

"Why am I still seeing the old edition of modelflight when you have told me that the new issue is up on the web?" is a question I quite often get asked by modelflight readers, who naturally think something has gone wrong at my end or on the web server itself when this occurs to them. But the truth is, when that question is asked, the old edition is simply NOT on the web at the usual modelflight web address for anyone to see - all the old text and picture files have actually been overwritten or deleted from that server! So what is going on, and where is the old issue coming from?

The answer is that the old issue is actually coming from YOUR computer because it has been stored in a special memory area on your PC known as 'cache memory' (usually just referred to as cache, pronounced 'cash'). You are experiencing one of Microsoft Windows' features which is supposed to save you time but which, in fact, causes much frustration! (I imagine that other operating systems have something similar, but I am not familiar with anything other than Windows.) Cache memory is a temporary storage area where frequently accessed data can be stored for rapid access. One type of limited cache memory, managed by your web browser, stores all the data from web sites you visit and then, if you visit the site again within a reasonable period of time, it loads the data from the cache memory instead of re-fetching it from the web. That's all very well, except if the website in question has been altered since you last viewed it, you still see the version that is being held on your computer instead of the latest version which is held on the web! You can find the contents of your browser cache memory in the Temporary Internet Files folder on your PC.

So, translating that specifically to modelflight, when I tell you that the April issue, for instance, has been uploaded to the web and awaits your visit, you eagerly press the link provided in my reminder email to see my latest offering! Your computer checks the cache memory and finds it still has modelflight (www.modelflight.regheath.com) stored there, so it sends that to your screen but it is, of course, the last issue you viewed, which would be the March issue! And it will keep on doing that until modelflight gets pushed out of cache memory by other sites you have visited.

One way of dealing with the problem is to press the Refresh button in your browser window, or the F5 key along the top of your keyboard. The Refresh process is designed to 're-draw' your screen and this sometimes - but not always, it seems - has the effect of clearing the page you are viewing out of cache and re-loading it from the web, so you will then get the latest version of that page. Another answer is to clear out the content of your Temprorary Internet Files folder or prevent stuff from being held there in the first place, but this you may not wish to do (see box, right).

Clearly, this does not happen to all websites, even if you do nothing about managing the cache memory yourself. It would be hopeless if this happened to certain commercial sites - you wouldn't want to go to your online banking website and find you were always looking at last week's balance, for example! So there has to be an answer, and although I did not know what it might be, I reckoned I knew a man who did!

I had a natter to my son who works in software development for one of the UK's banks, and he has found me a simple bit of code which I have now inserted into every page of modelflight which tells your computer that modelflight does not want to be stored in cache, thank you very much, and prevents it happening - so once you are successfully viewing this issue, it should no longer be a problem from here on in as far as modelflight is concerned!