Why is the 868 MHz antenna better than the Chinese antenna that looks identical?

Most Chinese antennas contain a wideband half-wave dipole built for both 868 MHz (EU) and 915 MHz (US) at once and therefore tuned to roughly 900 MHz — off-resonance in both bands. Our antenna is a quarter-wave radiator made in Europe, tuned to 868/869 MHz, with a measurement report.

Which cable do I need for the SAW filter?

A u.FL patch cable between the radio module and the u.FL filter, and a u.FL-to-SMA pigtail from the filter to the outside. Both are available in our shop.

Which Filter? Which Antenna? Which Cable?

Q: Which SAW filter do I need for my MeshCore or Meshtastic node?

For practically every device — node or repeater — the 2 MHz standard filter. It is the narrowest filter with the best filtering performance. Only boards with high transmit power such as the Heltec V4 or T096 need the 500 mW version.

The three most common questions from the MeshCore and Meshtastic community — answered briefly and honestly. Feel free to share this page in your group.

1. Which SAW filter is the right one?

We offer two 869 MHz filters. The choice is simple:

Standard — for almost everyone

2 MHz Standard Filter

The narrowest filter with the best filtering performance. Only 2 MHz bandwidth — LTE base stations (800/900 MHz) and other RF noise are suppressed as much as possible.

Use this filter for every device — node or repeater.

with u.FL → SMA, solder yourself →

Only for high transmit power

500 mW Version

Rated for 500 mW continuous. Only required if your board transmits at high power — above all the Heltec V4 and the T096 (both 500 mW) or boards with an external PA.

For all other devices it brings no advantage — the 2 MHz filter filters better.

with u.FL → SMA, solder yourself →

Rule of thumb: Heltec V4 or T096 → 500 mW version. Everything else → 2 MHz standard filter.

Both filters are our own PCB design, hand-soldered in Germany and individually tested on a network analyser. The 433 MHz variant is available here.

2. Why is our antenna better than the one that looks identical?

A fair question. The typical rubber-duck antenna from the node bundle or from AliExpress looks exactly the same from the outside. The difference is inside — and it is significant:

What is inside the Chinese antenna

Usually a wideband half-wave dipole designed to cover as many frequencies as possible “somehow”.
Worse still: it is built for both LoRa bands at once — 868 MHz (EU) and 915 MHz (US).
To make that work on paper it is simply tuned to ~900 MHz — off-resonance in both bands. In Europe you are transmitting a good 30 MHz away from resonance.
No measurement report, no information about what is actually inside. “868/915 MHz” on the sticker means exactly that: a compromise for both.

What is inside our antenna

A quarter-wave radiator (λ/4 monopole) made in Europe, specifically tuned to 868/869 MHz — the exact band MeshCore and Meshtastic use in Europe.
Measured: VSWR 1.04 at 868 MHz, 91 % efficiency. The transmit power goes into the air, not back into the radio module.
Full measurement report from the manufacturer — see the pictures in the product listing.

In short: Same look, different insides. An antenna resonant at 900 MHz is simply the wrong antenna for 868 MHz — no matter how many “dBi” the sticker claims.

→ 868 MHz Antenna +3 dBi SMA, hinged · Does your board have RP-SMA? Then you also need an RP-SMA adapter — coming to the shop soon.

3. Which cable do I need?

Most boards (Heltec, RAK, T-Beam, T-Echo …) have a tiny u.FL (IPEX) socket on the radio module. The u.FL filter is simply inserted in between:

Radio module (u.FL) → u.FL patch cable → SAW filter (u.FL) → u.FL-to-SMA pigtail → antenna (SMA)

u.FL patch cable 10 cm — from the radio module to the filter.
u.FL to SMA female pigtail — from the filter to the outside of the enclosure, where the antenna connects. If your board already has a pigtail, just plug it into the filter.
Filter without connectors (SMA variant): SMA socket and SMA plug for PCB mounting, solder yourself — then the filter sits directly between board and antenna.
Adapters (SMA–SMA, SMA–BNC, RP-SMA) are listed under adapters & connectors.

One more note that matters to us: never let a radio module transmit without an antenna connected.

4. Small adapters that are often missing

In our experience a build rarely fails because of the filter — it fails because of a missing two-euro part. That is why we stock the common adapters as well:

SMA female to SMA female — to join two plugs, e.g. pigtail to an antenna with a plug.
RP-SMA adapter (for boards and antennas with reverse SMA) — coming to the shop soon. For soldering, RP-SMA male / RP-SMA female for PCB mounting are already available.
SMA female to BNC / SMA male to BNC — for test equipment, handheld radios and existing BNC antennas.

All adapters and connectors in one place: adapters & connectors.

What is coming next

The range is growing. More items around MeshCore, Meshtastic and SDR are in preparation — among them further filters, low-noise amplifiers and accessories for outdoor use. Everything we add is measured here first; whatever fails the test does not make it into the shop.

This shop grew out of the mesh community and lives from it: the filters were the answer to a problem many of us had with LTE interference at the repeater. From the community, for the community — that is how it should stay. Thank you for the support, the feedback from the field and the recommendations in the groups. That is exactly what makes these small projects possible.

We ship across the EU. Within Germany shipping is fastest; for other EU countries see our shipping information.