I would like to compile the latest and greatest antenna recommendations on this thread.
So far, I have used the T-Beam 1.1s with SX1278 at 433 MHz (LongSlow, 20 dBm Tx Power) with these antennas and I only get about 1 KM of range even with a line of sight. I do not know if it’s because of my boards, interference, or simply because the antennas suck.
The stock antennas that come with T-Beams are crappier than these.
I am looking forward to suggestions for antennas that are portable. Omnis, directional antennas such as Moxons are welcome as suggestions too. I would request you to not mention huge ( like 5 feet ) antennas on this thread as most users use mobile nodes. I will create a separate thread for that.
All of these small type antennas are NO antennas but dummy loads, have no radiation patern.
Antenna is the most important element from your whole radio setup
Example, on 433 when i have 100 Watts put in 5 cm Wire, no one will hear me.
Put 100 Watts in UHF base antenna on 10 meter above ground, my range will be minimum 30+++ km
433 use COMET, DIAMOND or SIRIO UHF base antenna price +/- 50 - 90 USD/EU
868/915 use SIRIO base antenna +/- 50 USD/EU
Live in heavy city area surrounding buildings, use 4 dBd
Live in open country area, use 10 dBd
These antennas will stand at least 15++ years on a roof top
If you not spend money to buy good antennas, you never get maximum range out of your device.
In all antenna situations … Hight - high - higher - very high… is the magic word.
I just did my first test with two 433Mhz lilygo ttgo tbeam
on 10mW while walking the dog. I used a half wave antenna on both devices and I am totally impressed !
Or did you perhaps harm your transceivers by powering
the devices without antenna ?
With 34cm they a little bit unhandy and the Retevis RHD-771 are even heavy.
For 915Mhz, I reached 1.5km with PCB antenna in the urban area, external antenna such as whip antennas theoretically have better performance than most of PCB antenna designs due to the size limitation. To some extent, bigger is better. Attention, some antennas just have big cases but the antenna is actually very small inside. 433Mhz could reach at lest 1.5 to 2 times distance than 915Mhz for outdoor application if the RF front end was well designed.
On the other hand, it is very difficult to find a well-designed antenna in the Chinese market, and most companies that design antennas do not have professional designers. Sometimes even the VSWR parameters of the antenna are good, but the radiation efficiency is very low.
This product is from a reliable company. They used center feeding point for relative stable center frequency. This is more like a dipole antenna and this approach will downgrade some radiation efficiency.
Moxon Antenna is a directional antenna. Use this antenna if you just need to communicate with the person directly in front of you. I’m wondering if this is the design scenario of the meshtastic project
I’m not familiar with these two companies, they should be in the FPV area. I don’t know much about FPV, but using directional antennas to control the aircraft is very suitable.
Ps. Your communication range is normal, at lest not bad for a whip antenna with less than 5dBi Gain. About 1-1.5 km for urban area for 868/915Mhz band when TX power = 14dBm. 443Mhz may cover 1.5-2 times than 868/915Mhz band. However, it is also depends on the RX link design, such as Noise Figure and insertion loss.
From my research, Moxons have an almost 180-degree field of radiation in the front. I am planning on using the Moxons to connect 2 stationary nodes 7 kilometers apart.
From what I understand, it “concentrates” radio waves in the front, while “ignoring” the ones on the back. For my goal of connecting 2 far away stationary nodes, I believe it’s better than Omni whip antennas.
I tried with 433Mhz and I got only 700 meters range in Urban as well as forest areas. Not sure if the 433 boards suck, or my antennas.
After consulting with some people on the forum and discord, it turns out that the SX1262 on 868 MHz seems to be the board breaking range records over at the Range results thread.
I have only one functioning SX1262 838 MHz device right now, waiting for more devices and antennas to test with.
I am not sure about the real factors which affected your range results, too many factors may cause performance degradation. According to my personal experience, well designed 433Mhz always has better coverage than well designed 868/915Mhz design under outdoor env when setting to same TX power etc.
For your application scenario, you may use Moxon Antenna, however according to their datasheet, the Gain: 5.6dBi(2.4G)/5.7dBi(915M)/5.7dBi(868M) . Let us assume your current antenna is 0dBi, you will have 6 more dB for link budget after replacing antenna to Moxon.
In theory, your communication distance can be increased from 700 meters to 2800 meters. In reality, there is far from being such a big improvement. So, still can not reach 7 kilometers.
Free Space Path Loss: 129.8 dB @ 433MHz
They need a high gain antenna, could be very large and mount the antenna at a high place If they didn’t increase the TX power.
I did some research and turns out 868 MHz works better at penetrating dense materials.
Either way, I think these 433 boards do have some hardware problems as well. There’s a lot of folks on the forum here who get very crap results with 433.
I was a 433 supporter until I did my own real life experiments.
In the meshtastic world, I highly recommend avoiding 433 for now.
If 26 inches length of antenna for 868-915 MHZ is not too big for your application there is a simple DIY antenna you can build in few minutes and cost of less than $5 with beamwidth of almost 120 degrees and 10 dBi gain.Link below is for 2.4 GHZ but you can scale it for any frequency.
If you like to make it almost Omni directional replace reflector with a copper wire in length of both AA and it will have gain of almost 8 dBi in front 120 degrees and about 5 dBi all other directions.
If couple of pivots like telescopic antennas are used with careful construction it can fold into 13 inch when not in use.
If they didn’t increase the TX power.
