Makes sense to leave it then for sure and 24km punching through Vancouver downtown is certainly good enough for me. I’ll probably get the 22dbm rated board at some point since it also has the updated GPS. Hopefully a 30dbm board is in the works by some supplier, though even with just my own testing at home, a correctly tuned antenna is a far easier way to increase performance.
Did you tune your own, or buy good ones?
One of my stock 915 antennas was pretty good. The other one I bought off Amazon. I think digikey or mouser.ca are the place to go for good antennas. Amazon is no better than Aliexpress sometimes.
I’ve been pinging off-of your units once in a while, excellent to see those results. We’ve done Queen E to Richmond/North Shore using stock equipment, I’m very impressed!
13 miles from parking lot to mountain to mountain. MITM board was running headless.
Heltec LoRa units with stock included antennas.
24 miles point to point. Heltec LoRa boards. One set up on a prominent mountain top as a node powered by solar and a 3000mAh battery.
This is pretty incredible. Thank you very much for taking the time to let the world know about your efforts. Which specific antennas are you using?
Just the included antennas in the Heltec kits. Haven’t branched out into any aftermarket antennas yet.
Do you think antenna makes big difference?
If so for the price they are very good.
I think so…
The portable unit at the 166km range test was showing 0% signal strength but when I got back to the other node on the fence it was showing the signal being received at 35% I think that was partly due to the antenna on the node on the fence not being as efficient as my portable units this is what it looks like on my nanovna:
Fixed (Unit on the fence):
The portable unit is showing a swr of 1.04 at 860mhz where as the fence unit was 1.44, so much worse.
I am still an very much an beginner with antennas but from my testing the portable antennas are decent.
I am not sure if they ship internationally they are New Zealand based company so local for me (no affiliation)
As always with super long range testing LOS is the most important factor the earth being a globe doesn’t help
I wouldn’t say “much worse”, as 1.44 means a mere 3,2% of power is reflected by the antenna back to the transmitter instead of being absorbed.
Also, that has not much to do with gain and radiation efficiency, which is what we are really after. Unfortunately these are very hard to measure for amateurs like us!
That’s what ultimately matters!
@Ol_Dave I live In USA and the store you linked obviously have antenna tuned for 868mhz frequency. So I went to manufacturer website to check if I can buy same type of antennas for 915mhz frequency.
Surprisingly, They do not even show your models on their website. The website is linked below:
I would be interestedin buying few of these antenna for 915mhz if someone know an online source ?
I am unsure of if you could find better locally? I do not have a large sample size of antennas for comparison. If you want to test the 915mhz version of the antenna I have and you get stuck finding them PM me and I will investigate shipping you some.
I assumed store in NZ won’t have 915mhz frequency but on replacing 915 for 868 in model number I found the antenna and I ordered 5 of them for only $4 shipping which is very good.
Thank you again for sharing your experience and the link.
915mhz is also used here so yeah they do
Be keen to know how you get on with them
@Ol_Dave I will keep you posted when I receive it.
(With a heltec esp32 v2 with the stock antenna, and recent code level, at long-slow level.)
So, far I’ve managed 2.5 km across Lake Mendota, there was a garage right in the line of sight though.
I have noticed a lot of rebooting, though most seem associated with low voltage on the battery.
I’m looking at directional antennas, though I’ve read stuff about needing to reduce the power to avoid breaking regulations?
Two days ago I ran a long range test and reached a straight line distance of 3.5 km, I know I’m theoretically capable of going further, to 10 times or more, but for me it was exciting to experience such a long distance in person!
I used a 433 / 470 MHz stock antenna with a 2.5 * 2.5 cm area multi-frequency positioning module, the farthest distance I tested in the city was 235 meters, this time I tested in a suburban area with an open line of sight, one node was fixed at a height of 8 meters from the ground and the other node moved towards a lower altitude to test (about 35 meters drop in altitude) and finally at about 3.5 km I was still able to send messages, with no buildings between the nodes, only few trees and some cables. I tried to go farther and failed to send the message.
I went again where there were villages and farmland between the nodes and was also able to communicate for more than 2 km.
Also, to my surprise, up to 22 satellites could be searched in the open field, which is really a lot.
Dear colleagues, I propose to calm your ardor and fantasies regarding the power of LoRa modules. Wherever 20dBm or 22dBm is written, it has nothing to do with reality.
I took measurements of several proprietary modules. On 1276 chips, the maximum output level is +16 … + 17dBm.
On 1262 modules, the output level + 19dBm can be considered fair. There is no question of any 22dBm there, not even + 20dBm.
Let’s agree that 0.5dB is lost on transitions. It turns out that a clean level of 19 dBm comes out of the module.
In most cases the limit has nothing related to the hardware…
In the SX1276 datasheet the Semtech does not guarantee that the permanent transmit activity @ 20 dBm will not fry the chip when the antenna has a ‘short cut’ or not connected.
In our firmware ( SoftRF ) we do not want for a crazy customer to do weird things then complain to the manufacturer or seller for a moneyback.
So the max. transmit power is intentionally restricted to 17 dBm - which is ‘default’ limit written in the datasheet and considered to be safe (fool-proof) enough.