I believe for urban areas, low gain is suggested. I'm in a suburban area, and after testing I found my repeater did better with a 2dbi antenna than a 6dbi.
What if there is no node in my area? Will a high gain antenna reach farther nodes?
Also, do you have a suggestion for the antenna, or should I just try using the included one and buy another if it doesn't work? I'm worried it might be a 915 antenna instead of 868, because the device allows choosing the frequency.
A high gain antenna helps reach weaker signals. It also increases the amount of local noise that is received, and if there are multiple nodes nearby, could cause a lot of cross talk interference by nodes stepping over each other. It is a tradeoff between range and the electrical noise profile of your immediate area, which is why low gains work better in urban places.
Seeing as antennas are easy to swap I'd just run the included one and see what it does. If you don't get any activity go up to the 6DBI.
Antennas achieve "gain" by sacrificing radiated power in some directions to favor others. For omnidirectional antennas, this means flattening the pattern: less radiated energy off the end, and more perpendicular to the antenna. If you are mobile it is possible to take this too far.
In my experience, it is hard to beat a simple quarter wave ground plane or whip antenna in typical applications. It's not hard to make one, but if you are buying one you shouldn't need to spend much money on it.
I can tell you for a fact that a 10 DBI antenna is far too high gain for a normal day-to-day node. You want a 3 DBI, or 5 at the absolute maximum.
With high gain, you get a good distance out of your antenna at the sacrifice of not being able to hear notes above and below you.
The 10dbi gain claim is marketing, it's not going to get anywhere near that. A Yagi antenna could get that but this is a very basic half wave whip.
So, what gain do you think I can expect from that antenna?
Don't worry so much about gain, for your sanity. When buying antennas, it's usually just a number they made up. Gain is a measure of the directivity of the antenna's radiation pattern, so a 10DBi gain antenna would be very different antenna like a Yagi antenna that has to be pointed directly at a another radio to work.
The advice about 1/4 wave antennas is good. Antennas need to be a fraction of the wavelength of whatever frequency they operate on. 1/4 wave is sort of the standard antenna that always works well. I prefer 1/2 waves myself, the radiation pattern is not all that different but a little better in the horizontal and they work better without a ground plane.
1/4 wave for 868MHz is around 3in or 7.6cm and 1/2 wave is around 6in or 15.2cm. So, basically, any antenna around 3 or 6in or 7.6 and 15.2cm should give you the best performance in antennas of this style and size. The giznot is 17cm, which I assume is a 1/2 wave plus the base.
When it comes to Meshtastic, I'd say the longer antenna will be better, but if you want to put your device in your pocket or something, a shorter one will be fine too. The good thing is, the antennas are pretty cheap. If you get the Giznot you can also get a 3 inch antenna for like $3 and use them both.
I see, thanks for the advice. I'll probably do that
The Part List section at this listing specifies the included cable has a RP-SMA socket. If the one at whatever listing you're looking at has the same port, then you're probably good. But who knows. You can also ask the seller, but ali sellers are sometimes airheads.
The Ali seller in question should be the official seeed store, so I should be fine
A community to discuss Meshtastic (https://meshtastic.org/docs/introduction)