I got a Saturn set as my entry into 2.4GHz. 4 proportional channels and one on a switch, and it was priced so as not to break the bank. The extra receivers are not the cheapest, BUT when you look at the cost of a cheap 27MHz RX then add the cost of a pair of crystals, it looks a lot better.

Yes, they work on surface craft. You do need to be careful where you mount the aerial on the RX as it will be very short and they are very line of sight.

I've handled several of those stupidly cheap radios and I wouldn't put one in any model which I wasn't prepared to lose or damage. They are cheap because they are made to go into toys which by their nature don't last for very long, and they are stupidly cheap because they use poor-quality or even reject-grade components; are badly assembled by low-paid workers and have no Quality Control.

I was talking to a guy very recently who insists on buying the very cheapest speed controllers he can find, direct from China. He buys them in tens. When I asked him why, he told me that that – of the ten – only four would work at all and of those four only one would continue to work. When that one finally goes bang he buys another ten. At four pounds each that means he pays £40 for one poor-quality ESC which is pretty much bound to go wrong sooner or later. Utter lunacy.

Only by cutting every corner possible can electronic equipment be made for that price. As I wrote somewhere once, if you pay a lot then you might not get everything that you expect, but if you pay peanuts then you'll most likely get everything you deserve. I've stated publicly that I wouldn't pay any less than £80 for a Tx/Rx 4-5 channel combo; I've seen nothing to change my opinion.

Dave M

I would definitely not use the cheap Chinese radios in aircraft, where a malfunction can be disastrous, however I am quite comfortable using them in boats. I have three of the cheap 2.4 ghz radios and have not yet had a problem with any of them, after up to four years of regular use. I completely understand Dave M's position on this, and I have a great deal of respect for his expertise in these matters, but I take the view that the worst that could happen to my slow model boats is that they cease to respond mid-lake. Should that happen which – touch wood – it hasn't so far, then it would be time to launch the rescue boat. I would also not use them in fast electrics where a malfunction could cause damage to other boats.

Peter.

If you have a stupid-cheap Chinese radio which works for you then fine – it works for you. By the same token there are a lot of people who happily drive round in cars which are mechanically unsound and offer little protection in the event of a crash. As long as you're prepared for the possible consequences of buying the cheapest XYZ on the market then that's OK by me. Suit yourselves, chaps, and good luck to you.

I've seen and heard nothing to change my opinion, but it's only my opinion.

DM

I was trying to talk about ALL the changes that have happened in modelling since the 1980s, to provide Rob with a bit of background, rather than a discussion on favourite radios……

Actually, I was thinking of going wider than that!

Radios are cheaper, and have more functions, true. And the move to 2.4Ghz allowing people not to worry about frequency clashes is a big difference. But if you have come back into modelling for the first time since the 1980s, there are other things – a few of which you mention, like mini servos small enough to mount IN a control surface and LiPos. Brushless motors is a biggie. Outside eloectronics there are new materials and the spread of specialist glues. The arrival of national and international modelling forums on the web.

And the downsides. Fewer model shops. Many fewer venues to fly or sail. The move from built-up models to ready-to-run. The rise of internet purchasing. Are the last ttwo bad or good…?

2.4Ghz radios:

– are generally cheaper than the old lower frequency radios. And have a very small aerial.

– Same Tx can be used for air, car or boats. But not submarines. TXs are usually designed for airplane, car or helicopter/drone operation, rather than boats…

– don't have a specific spot frequency that they work on, and don't use exchangeable crystals. Instead, each company's transmitters only work with a specified model receiver. Each specific receiver is 'bound' to a specific transmitter, often by pressing a button when the two are in close proximity. Thereafter, that receiver will only respond to that transmitter.

– are better at rejecting interference than the older radios.

– will allow very many models to operate simultaneously, with no need to check frequencies with other users.

Brushless motors:

– come in two types, inrunners and outrunners. Inrunners are high-speed, out-runners are high-torque

– require a brushless speed controller to work. They won't work on their own, or with a brushed speed controller

– have 3 wires going into them, which are connected to the 3 wires coming out of the controller, in any order. To reverse direction, reverse any 2 of the wires.

– brushless speed controllers often undertake a process called 'programming' when they are attached to a motor. This can be confusing to new users, and if you have poor Chinese instructions this doesn't help. Incidentally, another reason to be cautious of cheap Chinese equipment is the lack of coherent instructions and after-sales support…

– Can put out alarming amounts of power at very high revs , from quite a small, light unit.

– unless you get a special expensive 'sensor enabled' motor and controller, they are not very good at low speeds. In particular they tend to start with a jerk. 2.4Ghz transmitters and brushless speed controllers often have specific failsafes built into them requiring users to drop the throttle to low power before the motor will start.

– need a good high-output battery to provide the power they are capable of. This doesn't have to be a Lipo, but for aircraft it usually is…

– are very difficult to size for a particular model, since the same motor is usually capable of running on a wide variety of voltages (sometimes 20v or more) and providing a wide variety of power outputs. They use a measure called 'KV' – look it up…

LiPos:

– are very light batteries with low internal resistance, capable of holding a lot of power and releasing it quickly.

– comprise 1 or more cells, each with a nominal voltage of 3.7v. Fully charged they are 4.3v, discharged they are 3v.

– are very dependent on proper handling, charging and discharging. Exceeding limits by a minor amount can damage the battery, and so a specially precise charger is used. If the batteries are damaged, they may ignite fiercely, so care needs to be taken with them at all times, and specific handling procedures adopted. Continuous battery monitoring is recommended.

– Brushless speed controllers often monitor the battery they are connected to and cut power if unsafe LiPo voltages are experienced. This feature is set up during programming, and can be very confusing if you do not realise what is happening…

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