Do I need a stronger/bigger antenna?


#1

I am going to be putting my Nova in a rural area, between 5 to 10 miles away from multiple cell towers, with line of sight to them.

Will the stock antenna be sufficient? I’m wondering if I should I get a directional antenna and if my Raspberry Pi Zero supplies enough power for a larger antenna.


#2

Hi, I’m not an RF expert, but I think you’ll have to do some testing.

I am deploying NovaM devices in some rural areas. I’ve done some field testing (measuring signal strength with AT+CSQ) in rural Mississippi with two different antennas. I have subsequently obtained four more antennas from Pulse Electronics. I will be returning to MS in a couple of weeks for more testing. I live in a suburban area where the signals are not so weak. The signal strength has varied significantly with the antenna. Using the stock antenna as a base, some performed much worse and some performed up of 5 or 6 dBm better. All of the antennas I tested are smallish and were attached directly to the NovaM.


#3

Do you have an estimate on the distance from the tower? Also, did your tests have anything blocking the antenna (I’m putting mine in a pvc pipe)?


#4

Power output is limited by the modem so a beefier power supply will not get you more RF power. The supplied antenna is actually pretty good, about as good as you will get with an omnidirectional dipole antenna. Although plastics do have an effect on RF performance and the antenna patterns they are minimal compared to any metal (including the Nova itself) so keeping your antenna away from large metal planes like filing cabinets, metal boxes, etc will keep you from being blocked or have reflections effect the quality of the signal.

Your next option as you mentioned is a directional antenna, Note these might violate FCC requirements as I believe you are limited to a peak directional gain of like 3-4dbi. Also be careful of antennas that have or require long RF cables. Having a 6dbi gain antenna with 15 feet of crappy RF cable will probably perform worse.

Also only look at antennas that have a datasheet with antenna patterns, random crap of amazon / ebay / etc will likely do no better than the provided antenna.

Lastly note that monopole antennas need a ground plane to work effectively (they need to be mounted perpendicular to a metal surface with the metal surface shorted to the jacket of the RF cable). Otherwise these are also pretty junky.


#5

Interesting. I don’t plan on upgrading the antenna after all (too expensive), but I’ll share my basic research for those who might stumble across this post.

Wilson Yagi Antenna 301111
Wilson Electronics Ultra Low Loss Coax (10 ft)
Lightning Arrestor (this is a super cheap one. wilson recommends this)
U.FL IPX to SMA Adapter

Thanks for your help.


closed #6

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