how can i extend the range of my kids' RC car ?

it is 40MHz .. and i want to extend its range ...

can i use this RF amplifier ?
**broken link removed**

thanks

No, the referenced circuit is a small-signal amplifier; you need an RF power amplifier. Besides, the 40Mhz toy operates at a low power in a license-free mode. It is not legal to raise the power level and operate it in that frequency band. To get more range, you will have to spend more money to get a radio-control which has more range (and operates at different [legal] frequencies).

Antenna amplifier

Here is a simple antenna amplifier.
I would suspect the problem is one of signal to noise so you may not see much improvement, but who knows?
You might be able to get some improvement by bypassing the brushes on the motor to reduce the noise side of the equation. Try a .01 ceramic cap from each motor lead to the motor case and one across the motor leads.

Here is the rest of the info on the amplifier.

Use around 470uH coil for L1 if you use for AM frequency (700kHz-1.5MHz) and use around 20uH for SW or FM receiver. For short wave performance, using this antenna booster, you’ll get a strong signal as we get from a 20-30 feet antenna, with only a standard 18? telescopic antenna and this booster circuit. The power supply should be bypassed by a 47nF capacitor to ground, at a point that should be chosen as close as possible to L1.

MikeMl said:

No, the referenced circuit is a small-signal amplifier; you need an RF power amplifier. Besides, the 40Mhz toy operates at a low power

Click to expand...

Why this small-signal amplifier is not suitable ... while u said that this toy is operating at a low power ?????

MikeMl said:

To get more range, you will have to spend more money to get a radio-control which has more range

Click to expand...

OK for money ... how much ??? ... and what is the cct. suitable for this ???

we had a RC transmitter that used a 9 volt battery. Using a 12 volt battery increased the range and apparently, never burned out the transmitter.

@mel8030

ok .. that sounds interesting ... by how much did the range inrease after raising the i/p voltage of the TX ????

and where is the cct. as well ?

Most cheap RC toys use a horrible but simple and cheap super-regenerative receiver. A good RC receiver has super-heterodyne circuit like real radios have. The differences are sensitivity, selectivity and cost.

My new RC model airplanes and helicopter use 2.4GHz and have a range that is farther than you can see. The circuits are very small and lightweight but are not cheap. Today a hawk chased my P-51 Mustang around the sky and although I could loop around him and out-manoeuvre him he took a bite out of my airplane.

ok audioguru .... where can i find these RC toys of u ??? and what is their range ?

Your local RC hobby store. Check your yellow pages.

My RC model airplanes are Ready To fly. Open the box, charge the supplied battery with the supplied charger powered from the supplied AA cells and when the charger shows that the battery is fullly charged then connect it to the airplane and go to a park. Use the supplied AA cells in the supplied transmitter and fly the airplane.
The range is farther than you can see.

If the range is based on vision, then it all depends on how far you can see, the further your vision, the further the range.

I have an RC plane (Megatech, Freedom Flyer) that doesn't really fly anymore because of too many crashes, but when I got it the range of the transmitter was about 1/4 of a mile. Until a low flying plane passes overhead, then it goes out of control and crashes into the ground like a stone. A police helicopter was hovering near my house for about an hour, and the plane seemed to have a mind of it's own.

My radio is just a tiny little 4 channel 27MHz transmitter. I'm sure that a high quality RC system like the ones that AG uses would be a lot better.