I use wAP LR8 LoRa GW with external antenna. Is there a recommendation for maximum cable length between GW and antenna? The delivered 1m antenna cable is to short for my application. Is 4 - 5m still feasible?
Thank you for your support.
If you’ll use decent cable, signal loss will be a couple of dB. If peers are not too far, then those few dB signal loss won’t be critical.
Any cable length is feasible - provided you don’t mind losing the range. Every dB of cable attenuation costs you some kilometers of the maximum distance the LoRa transmitters can be away from your antenna. From attenuation point of view alone, you could replace this particular 1 m cable with a thicker one that could be proportionally longer for the same attenuation, but you’d have tough time arranging it mechanically. So think about a very short (10-15 cm) cable at the wAP end, connected to a longer 1/4" or even 1/2" one.
The product pages do not specify the gains of the antennas (neither the internal one nor the external one) nor the attenuation of the cable, so it is hard to say what amount of cable attenuation completely erases the advantage of the external antenna as compared to the internal one if they were placed at the same spot. That 1 m cable should have less than 0.5 dB attenuation at 860 MHz.
Given that the wAP is designed for outdoor installation, why is a 1 m cable too short for your purpose?
Thank you for your answers. I had a look to some antenna extension cables coaxial cable type CFD200 SMA - SMA which have about 0,55db/m attenuation at 2,4GHz which should be about 0,13db/m for 868MHz. So for 5m about 0,75db which in my case is OK.
In the datasheet I’ve googled for CFM200, they state 0.326 dB/m @ 900 MHz. So 5 m gives 1.63 dB.
Thank you for the correction!