# Wiring an RF-LoRa module to the Raspberry Pi

#### Janis59

Joined Aug 21, 2017
1,224
The range of LORA even without of very well built external antenna in the obstacles of large city is ca 3 km or more. We made this test few months ago at my place. It is uniquely sharp about to beat-through capability.

Joined Jan 11, 2018
3

#### Janis59

Joined Aug 21, 2017
1,224
25 km2=5km x5km.
It means You have very small deficit indeed. Firstly, I measured those 3 km in the city environment between the stone walls. PROBABLY in the clear field obstacles it may give those 5 km demanded. At least it may for sure to give it on any 2...3 dB altered (rubby) antenna like this www.ebay.com/itm/2x-6dBi-2-4GHz-5GHz-Dual-Band-WiFi-RP-SMA-Antenna-2x-35cm-U-fl-IPEXble-H9-C4G6/322952324454?epid=2240992264&hash=item4b31756566:g:CpYAAOSw3fZaPLQo

However, if You need to connect a 25 km DISTANCE (hope not), You’ve got a trouble. I have no a large experience on such distance with 2,4 GHz, but 0,47 GHz I had worked enough to know that boating expedition where we had first boat and last boat supplied with the soviet military P-105 radio-station with 50W power (You have seems 5 mW instead), we had in the river canyon understandable speech quality about 30 km at 0,15 GHz and 5 km at 0,47 GHz. Thus, the radio-horizon is MUCH more important than signal/noise ratio, given by good antenna. The word horizon here is much more important as radio, must be noted. Just use a tower in kind of "central" point, and distance will be got probably even just by original on-board antenna.

Other experience I have with the LORA on home measurement devices distantial reading. I mean hot and cold water or gas meters etc. If them are mounted in deep cellar some 2 or 3 meters under ground level, the distance is just 200 meters, by obligatory dipole antenna direction passing. If un-passed, maximum 50 meter. Then we elaborated wire-piece antenna what was bit better as those original (and for sure cheaper), but anyway it isnt optimal, so the 500 meter is still the unavailable for this aim. (Thus I am still interested to know everything about directed 2,4GHz antenna constructions what are relatively simple in mass production.)
One kind of it PROBABLY may be some aerial version of Slim Jim` like this https://amoghdesai.com/wp-content/uploads/2016/08/SlimJim-Dimension-for-TV-Feeder.jpg - only the dimensions must be passed to LORA frequency. At least this omnidirectional antenna has VERY narrow ray in the vertical plane, giving rather big boost to near-horizon directions. Yagi seems completely inappropriate because of mounting accuracy issues, double or triple quadrat (or loops) arent realistic too, so the rubber duck aka CLC antenna for this moment is most realistic candidate for long range signalling. However this www.dronetrest.com/uploads/db5290/original/2X/9/9d7f22772daafe0b04b47e0e2137ae139dcea477.png is extremely interesting, but I dont know much about.
But DONT forget the tower. The horizon is https://en.wikipedia.org/wiki/Horizon L=3,57SQRT(h) thus for 7 km distance You need AT LEAST the h=4 meters high tower. Actually, my experiment with LORA distance I provided from third floor window to guy walking with receiver in shoulder height.