Does Using Multiple 20mW Transmitters Increase Remote Control Car Range?

Click For Summary

Discussion Overview

The discussion revolves around the feasibility of using multiple 20mW transmitters to increase the range of a remote control car. Participants explore the implications of using low-power transmitters, potential interference issues, and legal restrictions regarding transmission power in the 433MHz band.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether using two 20mW transmitters could double the range of their remote control car, expressing a lack of knowledge about electromagnetic waves.
  • Another participant asserts that using two transmitters on the same frequency would lead to interference, potentially worsening the range or making it non-existent.
  • A participant mentions the importance of aerial length and suggests that fine-tuning it might help improve performance.
  • There is a concern raised about legal restrictions on transmission power in the 433MHz band, with a participant noting that they should keep below 20mW to avoid interference with other users.
  • One participant proposes the idea of using a MOSFET amplifier circuit to increase the power of the signal while using the module solely for encoding purposes.
  • Another participant warns against building an amplifier without proper equipment and knowledge, suggesting that using 2.4GHz transmitters might be a better alternative for increased range.

Areas of Agreement / Disagreement

Participants express differing views on the use of multiple transmitters, with some arguing against it due to potential interference while others explore the idea of amplification. Legal concerns about transmission power also create a point of contention.

Contextual Notes

Participants highlight the need for knowledge about electromagnetic waves and legal restrictions on transmission power, indicating that assumptions about interference and signal amplification may not be fully resolved.

Tesladude
Messages
168
Reaction score
1
I have built a remote control car, pwm speed controll and all, using picaxe microcontrollers and gained a lot of experience doing it.
I used a low power i think 20mw transmitter you can find all over ebay that uses a 433hz carrier wave. A long time ago i found a 1w transmitter meant to be a step up from the common 20mw i mensioned but if i do not want to use the larger 1W transmitter, then will 2 20mw transmitters double my range?
It may seem like an obvious question but i lack in knowledge reguarding electrmoagnetic waves and such.
Or will even using 2 recievers increase this sensitivity?
 
Engineering news on Phys.org
No you can't use two transmitter modules like that. Hard to know where to begin to explain but it won't work. The simplest answer is that the receiver will see two signals on the same frequency. One will appear as interference to the other making the range worse or non-existent.

I've not used these 433MHz modules but getting the aerial length right will be important. It might be possible to double the length for example. Fine tuning the length may also be necessary. It may also be possible to turn up the supply voltage to the transmitter module (some modules only and at your own risk). Google found..

http://forum.arduino.cc/index.php?topic=216467.0

Edit: Oh and well done for getting the project working!
 
Tesladude said:
I have built a remote control car, pwm speed controll and all, using picaxe microcontrollers and gained a lot of experience doing it.
I used a low power i think 20mw transmitter you can find all over ebay that uses a 433hz carrier wave. A long time ago i found a 1w transmitter meant to be a step up from the common 20mw i mensioned but if i do not want to use the larger 1W transmitter, then will 2 20mw transmitters double my range?
It may seem like an obvious question but i lack in knowledge reguarding electrmoagnetic waves and such.
Or will even using 2 recievers increase this sensitivity?

What country are you in? You probably are not supposed to be trying to increase your power in the 433MHz band above that 10-20mW -- there are other users in that band, and you are limited to low power for a reason, to avoid interference.

https://en.wikipedia.org/wiki/LPD433

.
 
I am in the US and didn't realize there was a law so ill keep bellow 20mw.
I really want a somthing plug and play, could I possibly take one f these modules and tap a mosfet amplifier circuit onto the antenna pin and take measurements in order to achieve a true 20mw thus using the module only for its encoder purpose and create a transmitter which will simply amplify the signal it creates and put that through a coil?
or what about the zab-3000 transmitter?
 
You shouldn't try to make an amplifier unless you have access to an RF Spectrum Analyzer and know how to use it to be sure that your amp doesn't have any harmonics that would violate the FCC specs for out-of-band interference. If you want more range, just use the 2.4GHz stuff that was mentioned previously. You can use a fair amount more power in that band, I believe...
 

Similar threads

Replies
1
Views
2K
Replies
4
Views
15K
  • · Replies 22 ·
Replies
22
Views
11K
  • · Replies 19 ·
Replies
19
Views
5K