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Your Reviewer

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: Hobby King 4-channel 2.4GHz RC system

PART 2: THE TECHNICAL STUFF

HobbyKing 2.4GHz internals

The transmitter circuitry is a simple two-part system that has the main logic on one large PCB near the bottom of the case and the RF circuitry on a smaller board near the top.

Construction of these boards and associated wiring is adequate but not stunning in quality.

What struck me immediately is just how easy it would be to transplant the RF board from this cheap $30 radio and use it in another transmitter you might want to convert to 2.4GHz.

HobbyKing versus iMax9X circuitry

Another immediate observation is that the 2.4GHz transmitter circuit is virtually identical to that used in the iMax 9X.

When you discover that both systems appear to be made in the same factory, it becomes apparent why this might be so.

Yes, it seems as if FlySky Hobby are the source of many of these new low-cost Chinese radio systems, including the iMax, HobbyKing, Turborix and others. It stands to reason therefore that they'll use common designs and components.

Physically the transmitter is a whole heap of plastic. There are no silky-smooth ball-raced stick units or brushed metal plates anywhere to be seen on this unit. But hey, we're talking about a $30 radio so nobody should be complaining.

The trims are strictly mechanical but seem to do the job. As with other low-cost radios with mechanical trims, you'll have to take great care not to bump them when handing or transporting the transmitter.

HobbyKing 2.4 front panel

The spartan front panel contains only a bind/range-check button and four reversing switches, one for each channel. Battery status is indicated by a single LED that changes from green through red as the voltage falls.

Although the bind button is labeled also as "range test", there appears to be no change to the system's range when this button is pressed.

battery compartment

One perplexing aspect of this radio is that it comes with space to fit eight AA-sized cells, presumably either alkaline or rechargables. That means it expects to see around 9.6V to 12V and although I haven't checked, I suspect that the low-voltage warning will kick in at about 8.8V.

A look at the internals show that a great deal of the power coming from those batteries will be wasted.

Why?

Well, both the logic and RF circuitry in this transmitter operate on 5 volts, produced by passing the battery supply through some low-cost linear regulators. This means that over half the power sucked from the batteries will be turned into heat.

Why on earth they didn't configure the transmitter to take just five cells or allow a 2-cell LiPo to be used defies explanation. The same observation is true for the iMax transmitter.

Page 3 (The Receivers)

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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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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!

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