Meshtastic, MeshCore, 868 MHz, and the Ham Radio Trap

Updated April 28, 2026. This article is a technical and regulatory awareness note for radio amateurs. It is not legal advice. Always check your national frequency plan, license conditions, and local regulator guidance.

Meshtastic and MeshCore are technically interesting systems. They make low-power LoRa mesh networking accessible, inexpensive, and surprisingly capable. A handful of small nodes can exchange text, telemetry, position data, and routing information without cellular service or the internet. For hikers, experimenters, emergency-preparedness groups, and radio amateurs, that is naturally attractive.

But there is a trap for hams in Europe and the UK: the common 868/869 MHz LoRa world is not an amateur-radio band. It is license-exempt short-range-device spectrum with strict technical conditions. That makes it very different from operating under an amateur-radio license.

The dangerous assumption is simple: “It is radio, and I am a ham, so this is ham radio.”

The better assumption is: “Every transmitted packet belongs to a legal framework.”

868 MHz Is Not a Ham Band in Europe

In Europe, the commonly discussed “868 MHz” LoRa range sits in the 863–870 MHz short-range-device area. In everyday language, many people call this “the 868 MHz ISM band,” but for practical compliance it is better to think of it as license-exempt SRD spectrum. That means operation is allowed only when the equipment and usage remain inside the defined limits.

Meshtastic’s EU_868 setting does not simply mean “use anything around 868 MHz.” The official Meshtastic radio settings document describes EU_868 as using 869.40–869.65 MHz, with a maximum of +27 dBm ERP and a 10% duty cycle. The default LongFast center frequency is 869.525 MHz.

That sounds generous compared with many low-power SRD sub-bands, but 10% duty cycle still means only about six minutes of transmission time per hour. That limit becomes very relevant when nodes start forwarding traffic, repeating packets, acknowledging packets, sending position beacons, carrying telemetry, or acting as fixed infrastructure.

Duty Cycle Is Not a Decoration

Duty cycle is one of the most important legal details in European LoRa operation. It is also one of the easiest to underestimate. A quiet handheld node that sends occasional short messages may stay well within limits. A fixed roof node, high-site router, public store-and-forward node, telemetry gateway, MQTT bridge, or emergency-style community mesh can be a very different story.

Meshtastic handles this relatively defensively by default. Its documentation states that EU_433 and EU_868 must observe an hourly 10% duty-cycle limitation, calculated over a rolling one-hour window. The device is intended to stop transmitting when the limit is reached. But Meshtastic also has an override option. The documentation warns that enabling the override makes the device ignore the European hourly duty-cycle limit and may violate regulations if the device transmits too much.

MeshCore also deserves careful attention. The MeshCore CLI documentation lists a configurable duty-cycle setting from 1% to 100%, where set dutycycle 100 is described as “no duty cycle limit.” The same documentation shows 50% as the default duty-cycle value for that command. That may be technically convenient in a lab or in another regulatory environment, but it is not automatically appropriate for European 868/869 MHz SRD operation.

This does not mean Meshtastic or MeshCore is “illegal.” It means the configuration, frequency, power level, antenna system, and traffic pattern determine whether the real station is compliant.

High-Power LoRa Modules Make the Problem Easier to Create

Another point that deserves much more awareness is the availability of high-power LoRa modules. This is no longer limited to small 100 mW or 150 mW hobby boards. There are off-the-shelf LoRa modules with integrated RF power amplifiers producing around 2 W, or 33 dBm, output power.

For example, 868/915 MHz modules such as the Ebyte E22-900M33S are advertised with a maximum output power of 2 W. There are also 410–493 MHz LoRa modules, such as the E22-400T33S, specified at 33 dBm output power and covering the 433 MHz / 70 cm area depending on configuration.

That matters because many users think in terms of transmitter output power, while the legal limit is often expressed as ERP or EIRP. In other words, the legal limit is not only what comes out of the module. It is what the complete antenna system radiates after cable loss, connector loss, and antenna gain are included.

For the European 869.40–869.65 MHz SRD segment commonly used by Meshtastic EU_868, the relevant figure is normally +27 dBm ERP, or 500 mW ERP, with the appropriate spectrum-access conditions or duty-cycle limit. A 2 W module is already 33 dBm conducted power before antenna gain is even considered.

Now add a roof-mounted collinear antenna and the situation changes quickly:

LoRa module output:          +33 dBm
Coax and connector loss:      -1 dB
Collinear antenna gain:       +6 dBi
Approximate EIRP:            +38 dBm

+38 dBm EIRP is about 6.3 W EIRP.
That is about +35.85 dBm ERP, or roughly 3.8 W ERP.

Compared with a 500 mW ERP limit, that example is not slightly high. It is roughly eight times over the limit. The collinear antenna may improve the link budget, but it also increases radiated power. On license-exempt spectrum, antenna gain is part of the legal equation.

This is a classic ham-radio misunderstanding in a new jacket. Hams are used to improving systems with better antennas, higher sites, lower-loss feedlines, and more efficient radiators. That is good radio engineering. But on SRD spectrum, the regulator does not only care about the module power. The regulator cares about what the station radiates.

Collinear Antennas Are Not Free Gain

A collinear antenna can be useful. It can flatten the vertical pattern, improve local coverage, and make a weak mesh more reliable. But on 868/869 MHz SRD operation, that gain must be included in the radiated-power calculation.

This is especially important for fixed nodes. A handheld Meshtastic node with a small antenna is one thing. A 2 W LoRa module feeding a low-loss coax run and a roof-mounted collinear is another. A hilltop node or repeater-style router is another level again.

The better the site, the more important compliance becomes. Good antenna placement, low loss, and high gain do not only improve performance. They also make it easier to exceed ERP or EIRP limits.

Why This Is Especially Tricky for Hams

Radio amateurs often approach radio systems from a capability mindset. Can we get more range? Can we route over a hill? Can we build a better antenna? Can we put a node at a high site? Can we keep a community network alive during an outage?

Those are good technical instincts. But 868/869 MHz SRD spectrum is not built around amateur-style experimentation. It is shared, license-exempt spectrum for many low-power devices. The rules are designed around limited airtime, controlled radiated power, and coexistence with other users.

That is why mesh networking can become awkward in this band. A mesh network becomes more useful when nodes repeat, route, acknowledge, and maintain network visibility. But all of that consumes airtime. The better the network works, the more likely it is to create sustained RF occupancy. That is exactly where the SRD model becomes fragile.

70 cm May Be the Cleaner Amateur Route

For serious amateur experimentation, the 70 cm amateur band may be a more honest and defensible place to explore ham-oriented LoRa mesh networking. That does not mean 70 cm is a free-for-all. It means the operator is at least working inside the amateur-radio framework rather than trying to stretch license-exempt SRD rules into a semi-permanent amateur infrastructure network.

In Belgium, for example, the BIPT frequency plan lists 430–440 MHz with AMATEUR in uppercase, which indicates a primary service in the national table. In the UK, however, RSGB describes the 430–440 MHz amateur allocation as secondary and subject to additional restrictions. Other countries may differ again.

So the statement should not be “70 cm is primary everywhere.” It is not. The correct statement is: check the national frequency plan, the amateur license conditions, and the local band plan. In many European countries, 70 cm gives radio amateurs a much clearer legal framework for experimentation than 868/869 MHz SRD operation, but the details remain national.

Using 70 cm also means respecting the amateur band plan. Avoid weak-signal segments, beacon areas, satellite segments, repeater inputs and outputs, calling frequencies, and locally coordinated channels. A digital mesh node should not simply be dropped onto a random frequency because the module can tune there.

Amateur Radio Is Not a Private Encrypted Data Network

There is another important difference. If a LoRa mesh system is operated under amateur-radio rules, then amateur-radio rules apply. That usually means callsign identification, proper station control, no commercial traffic, and no encryption or obscured messages where prohibited.

This is where Meshtastic and MeshCore need careful configuration. Many mesh users like private channels, encryption, or closed groups. That may be normal and sensible in license-exempt or private-device contexts, but it can conflict with amateur-radio requirements. Amateur radio is fundamentally a self-training and public radio service, not a private messaging network.

That does not make digital amateur mesh networking impossible. It simply means it must be designed as amateur radio: identifiable, controllable, non-commercial, and compatible with the national rules.

The United States Is Different, but Not Unlimited

The situation in the United States is different because the common 915 MHz LoRa area overlaps the 902–928 MHz 33 cm amateur allocation. That makes the US less awkward from a frequency-overlap point of view than Europe’s 868/869 MHz situation.

But even there, one must distinguish between operating as an unlicensed device and operating as an amateur station. The same hardware may be capable of both worlds, but the legal framework is different. Under US amateur rules, 902–928 MHz is available to amateurs, but the band is shared and amateur operation has secondary-status considerations. Under amateur rules, station identification, control, non-commercial use, and restrictions on obscuring the meaning of messages still matter.

So even in the US, “915 MHz is LoRa” does not automatically answer the legal question. The operator still has to know whether the station is being operated under unlicensed device rules or under amateur-radio rules.

Practical Awareness Checklist for Hams

Before installing a Meshtastic or MeshCore node as a radio amateur, ask the real-world questions:

• Is the frequency actually an amateur allocation in my country, or is it license-exempt SRD spectrum?
• If it is SRD spectrum, what are the ERP or EIRP limits?
• Have I included antenna gain and feedline loss in the radiated-power calculation?
• Does the protocol and configuration respect the allowed duty cycle?
• Can the device override airtime limits, and has that override been disabled?
• Is this a casual handheld node, or is it fixed infrastructure?
• If operated under amateur rules, does it identify properly?
• If operated under amateur rules, is encryption or message privacy disabled where required?
• Is the frequency compatible with the national band plan and local coordination?

The Real Message

Meshtastic and MeshCore are not the problem. LoRa is not the problem. High-power modules are not the problem. Collinear antennas are not the problem.

The problem is mixing assumptions from different radio worlds.

License-exempt SRD operation is based on strict limits, limited airtime, and controlled radiated power. Amateur-radio operation is based on licensed operators, station identification, technical self-training, non-commercial use, and public accountability. The two worlds can use similar hardware, but they are not the same legal framework.

For casual, low-duty, license-exempt use, 868/869 MHz can be perfectly legitimate when the device stays inside SRD limits. For serious amateur experimentation, high-site infrastructure, emergency-style networks, router-heavy deployments, or long-airtime operation, European and UK hams should think very hard before building on 868/869 MHz.

A properly planned 70 cm amateur implementation may be the cleaner route for hams. But it must still follow the national license, the band plan, station-identification requirements, and the non-private nature of amateur radio.

The key awareness message is simple:

868 MHz is not “the ham LoRa band” in Europe or the UK. It is tightly regulated SRD spectrum.

A 2 W LoRa module and a collinear antenna may be technically attractive, but on 868/869 MHz they can easily become non-compliant. The fact that hardware is cheap, available, and easy to configure does not mean the resulting station is legal.

Good radio engineering starts with the antenna and the link budget. Responsible radio engineering also includes the rules.

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