External Antenna for LoRa module

[d00m178]

Hello.

I need put my device with LoRa radio module (915MHz) to remote place and I need install external antenna for it because device will be covered in case and located under snow.
So I need advice - which radio cable I need use to bring out the antenna.
Will be ok to use usual coaxial TV cable ?
50 or 75 Ohm ?
And how to solder it to device - central wire to ANT pin and shied to GND ?
And at the end of the cable I need make ~8cm wire ? Or solder connector and buy some special antenna for my freq - 915 Mhz ?
I need working range about 200-300m.

Thank you.

[Felix]

What type of device are you using?

[d00m178]

Anarduino + RF96 (LoRa)
I believe that it is the same as Moteino.

[Felix]

Similar in some ways but also different. My suggestion is to get support in the Anarduino forum for Anarduino specific hardware, to ensure you get the most accurate advice for that hardware platform.
For the ANT you would probably want a 50ohm transmisssion line to your radio, center tap to ANT and shield to GND.
I cannot really advise on how you want your antenna connected since there are many types of antennas.

[d00m178]

Thank you!
Will use 50ohm cable.

Will be enough use as antenna just piece of wire at the end of the coaxial cable, 8 cm in my case (915 MHz)? 

[Felix]

Doesn't hurt to try, if that won't work then try a dipole or yagi.