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All of the products reviewed here have been bought with my own money and nobody pays me for the time I spend writing these articles.

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My Credentials
So who's doing this reviewing then?

Well I've been building and flying or driving radio controlled models for over 40 years and during that time I like to think I've built up a reasonable amount of knowledge.

I'm also a qualified electronics engineer who has worked in radio frequency, analog, digital systems and software for more than three decades. In fact I designed and built my first RC set back in 1969.

For the past nine years I've also been involved in the design and manufacture of some rather sophisticated engine technology and UAV flight control systems.

So, chances are I've been there, done that and have a huge pile of tee shirts to prove it.

Right now I'm heavily into 3D flying and enjoy all aspects of the RC hobby. I may be old but I don't feel it.

In the Pipeline

Here's just a little bit of what's to come on this site...

RC explained: Demystifying terms such as PCM, PPM dual conversion, single conversion, full-range etc., this feature will explain it all.

Cheap Chinese Engines: Just how good are those cheap Chinese glow and gas engines that sell for half the price of their "brand-name" equivalent? I put several to the test.

Build your own radio gear?: Back in the old days, building your own RC gear was not uncommon and now the arrival of 2.4GHz has made it practical again.

 

Review: FlySky/Turnigy/iMax 9x 2.4GHz RC system

THE RECEIVER(S)

imax 9x receiver

The receiver is actually two receivers which are joined by a usefully long three-wire lead. The larger main receiver has end-pin connectors for up to nine channels (even though only eight are active) and the satellite is very small and light.

Both receivers sport tiny 1/4-wave wire antennas. Although quite light (at 15g), the main receiver is not particularly small, measuring 50x34x15mm making it a big big for tiny foamies. The combined weight of both receivers is just over 20g.

It is good to see that even such a low-cost system offers true receiver/antenna diversity, since this is an essential part of avoiding lockouts due to shadowing or reflections of the 2.4GHz signal.

Although the manual makes no mention of it, the two receivers should be separated by at least a few inches and oriented so that the antenna wires are at 90 degrees to each other. The antennas themselves should also be kept well clear of any conductive items, including carbon-fiber. Failure to do this can result in very poor performance from any 2.4GHz receiver.

The FlySky/HK receivers have a good resistance to low-voltages and when tested, continued to work right down to 2.4V. However, once the bind-lights had gone out in the main and satellite receivers, they did not recover even after normal operating voltage was restored. That is bad -- but a situation unlikely to occur if your batteries or BEC are up to scratch.

How does it perform?

Now this is the bit I know you've been hanging out to read...

Now can a low-cost Chinese 2.4GHz radio really be compared to the far more expensive offerings from JR and Futaba?

Well for some types of models the answer is a resounding yes.

As mentioned at the start of this review, I've been flying the iMax 9X for several months now and really put it through its paces in my 3D profile models. These are aircraft with very large surfaces and over 50 degrees of throw so the tiniest glitch or lockout becomes very obvious.

The first time I flew the system I pretended I was a total novice and simply stuffed both receivers in without any regard for their spacing or orientation.

Sure enough, the model started glitching badly at just 100 yards or so.

Changing things around a bit, I left the main receiver in the wing of my profile but mounted the tiny satellite unit high on the fuselage. The main receiver's antenna was running parallel to the wing, the satellite sitting vertically, at 90 degrees to the wing.

After walking over 200 yards on the ground I figured it was safe enough to fly and no glitches or lockouts were experienced at any normal flying range -- in fact it gave me rock-solid control at all distances and attitudes. The only time I noticed any small hesitations in control was when I flew the model to the very limits of visibility by climbing vertically until almost out of sight.

Whether those hesitations were just a result of the difficulty in seeing the model or a loss of signal are very hard to say but I think it's safe to say that the system has perfectly adequate range for all kinds of helicopters and regular sport RC fixed-wing models.

Over the past four or five months, the system has been flown alongside JR/Spektrum and Futaba FASST systems with no problems at all. The area in which I fly is also overlooked by several cellphone towers and a public WiFi network. Nearby there is a suburb with plenty of houses using microwave ovens and 2.4GHz cordless phones, plus there's a school with its own WiFi network just a few hundred yards down the road.

Using a spectrum analyzer, it becomes apparent that all these sources contribute to a fairly "busy" 2.4GHz band, yet the iMax seems to have coped without problems.

Page 4 (Pros and Cons)

Video: The iMax 9X in use

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The Blog

Updated: 20 Sep 2012
Here's a blog that will keep you informed just what's going on behind the scenes at RC Model Reviews and also tells you a little more about myself.

How compatible are 2.4GHz RC systems?

23 Mar 2010
How come there's no compatibility between different brands of transmitters and receivers? Why can't you use a cheap Chinese receiver with your Futaba FASST radio?

How to get a product reviewed here

4 Mar 2010
Since this has become a very frequently asked question, I've posted this simple guide to getting your product, or a product you're thinking of buying reviewed here at RCModelReviews

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The Good Oil

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Heads-Up: 2.4GHz RC systems tested

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Review: Bushnell's $80 Speed Gun

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Review: TowerPro MG995 servo

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Review: SK90

2.4GHz

It's cheap but can it really stack up against other glow engines in the .90 market? Find out in this review.

Review: iMax 9X 2.4GHz radio

How does this cheap 9-channel 2.4GHz radio system perform when compared to big-name systems that can cost two or three times as much? Have the Chinese finally developed a real contender with the iMax 9X?

2.4GHz Explained

Does all this 2.4GHz stuff have your head spinning? 2.4GHz

I've done my best to demystify the whole subject so if you feel like a bit of learning, this is the stuff for you!

Fix That Engine!

How can you tell when your engine needs new bearings? Who has the best prices and service on replacements? Just how do you change them? Get all that information and watch a great video tutorial anyone can follow.

Chinese Servos - How do they stack up?

Servos

The Chinese are now churning out a huge number of very reasonably priced no-name servos. But are they any good?

Baffled by batteries?

Batteries Nicad, NiMH, Li-Ion, LiPoly, LiFePO4, A123... the range of different battery types has never been greater. So how do they differ and what type should you be using?

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