Kit 433 mhz- How to improve their range?

hello

i'm using rf kit working 2 arduinos.

after changing transmitter 1 module antenna, improved range 50 meters without obstacles.
in specifications, range it's between  500-800 meters.

the receiver haven't got antenna because works better without 1 ( antennas tried aren't antennas)

anyone have same problems kits?

here left tutorial code
     http://controlrobotics.rodrigomompo.com/2013/09/tutorial-arduino-kit-rf-433mhz-part4.html 

and specifications of transmitter

http://www.dx.com/es/p/zsd-t3-315-433mhz-ask-high-power-rf-transmitter-module-yellow-228289


probably best solution it's change type of transmitters, want explore limit of kits , write conclusions use kits.


thanks

Arduino Forum > Using Arduino > Networking, Protocols, and Devices (Moderator: fabioc84) > Kit 433 mhz- How to improve their range?

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