rf longer antenne

Hello

i have connected a rf 433mhz sender to my arduino. but 70m range. now if i make the antenne longer should thatwork? for example 50cm antenne will the rf receiver have mor range?

Thanks

http://www.qsl.net/kb5wck/antenna.html

// Per.

It say 20cm but works it too with a longer antenne

Antennas need to be resonant at the frequency they are used at , which means the length needs to be 1/4 wavelength long, or an odd multiple of that length. So an antenna 3/4 wavelength will also work, but wont be any better than a 1/4 wavelength. Any other lengths will be worse. 17 cm is the optimum length for a 433 Mhz transmitter.

mauried is totally correct.

And there are other factors that effect range, including orientation and polarization.

I’ve not tried it myself, but you could try connecting 50ohm coax to the antenna point (and GND) on the board, to feed a Yagi style antenna, or even build yourself some sort of dish antenna

As 433Mhz is effectively on the 70cm ham radio band, if you search for 70cm antennas you’ll find lots of info on how to build high gain antennas for this frequency e.g. this guy made a yagi out of wood, wire and nails

Okay.
Will it work to power the transmitter with 9v so that the range will be longer?

arduino123456789: Will it work to power the transmitter with 9v so that the range will be longer?

Depends on what it says is the maximum voltage on your transmitter data sheet. It might improve the range but it also might fry the transmitter.

Maximum voltage = 20 v but what do you mean with fry?

can any tell my how to change my transmitter for 1km or more range?

Fry means to damage or break, to render useless, to brick, to destroy.

You can not legally increase the range to that distance.

I'm not sure any ISM band transmitters operate at that range.

You probably need to replace your transmitter and receiver units, and if you are using simple AM units, you may need to use more complex FM units as they have better noise immunity and consequentially better range.

I did a quick search and turned up multiple modules that have longer range e.g. http://www.ebay.com/itm/RFC-1100A-CC1101-Module-Including-Amplifiers-with-High-Gain-Antenna-433MHz-/291090182510?pt=LH_DefaultDomain_0&hash=item43c653b16e

http://www.ebay.com/itm/3000M-0-5W-high-power-wireless-transceiver-module-433M-compatible-SI4432-/260924323612?pt=LH_DefaultDomain_0&hash=item3cc04d371c

However I suspect these modules can't be legally used in most countries, and I would not trust the claims made by the supplier in terms of the very long range one e.g 3000m. As 3000m may only be achieved for uninterrupted line of sight operation

Also I have no idea who you interface to these modules, you'd need to do your own research

Is it in the nederlands legal?