Antennas
The cheapest way to get more range
Information
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The antenna matters more than almost anything else on your node. A good antenna in a good spot will beat a more expensive board with a bad one, every time. If you want more range, start here before you spend money on anything else.
Never power on without an antenna
Powering a node on with no antenna connected can fry the radio chip. It's not a maybe. Always have the antenna on before you plug it in.
Match the frequency
This is the most common mistake. Your antenna has to be tuned for the band you're transmitting on, which on the Welsh Mesh is 868 MHz (EU_868).
A 915 MHz antenna, a 433 MHz antenna, or the little 2.4 GHz WiFi antenna off an old router will all work badly or not at all. If you're buying one, look for 868 MHz or 863–870 MHz in the listing.
Connectors
Different boards use different antenna connectors. The two you'll run into most:
| Connector | Found on | Notes |
|---|---|---|
| U.FL / IPEX | Heltec V3, smaller boards | Tiny and fiddly, easy to damage. Often paired with a pigtail adapter out to SMA. |
| SMA / RP-SMA | T-Beam, larger boards | Screw-on and much easier to work with. |
If your board has a U.FL connector and you want a proper external antenna, grab a U.FL to SMA pigtail so you can screw a normal antenna on.
SMA vs RP-SMA
They look almost identical but the centre pin is different. If an antenna won't screw on properly, or screws on but doesn't work, check you've got the matching type.
Gain and placement
- Height beats everything. LoRa is basically line of sight. Getting your antenna a few metres higher, or up to a window instead of down on a desk, does more than any antenna upgrade. For a fixed node, up high and outside wins.
- A little gain helps, but don't overthink it. A decent 868 MHz antenna somewhere in the 2–5 dBi range is plenty for most people. Very high gain antennas squash the signal into a flat disc, which is great on a hilltop but can miss nodes above or below you.
- Keep it clear of metal and walls. Radiators, foil-backed insulation, metal window frames and thick stone all soak up signal. The more open air around the antenna, the better.
Fixed and outdoor nodes
If you're putting a node outside as a repeater, a few extra things matter:
- Use a proper outdoor antenna with a good ground plane, not the little stock whip.
- Keep the cable short. Coax loses signal, and cheap thin coax loses a lot of it. If you need a longer run, use decent low-loss cable.
- Weatherproof everything. Seal the connectors against water, especially where the cable meets the antenna. Water in a connector will wreck your range.
The stock antenna that comes with your board is fine to get started, so don't feel you have to upgrade straight away. When you're ready to push for more range, a better antenna and a better position are the first things to sort. For help picking a board, see Node Choices, and to set your node up, see Node Configuration.