MultiNav Pro+ BLE 50km claim - what output power is it running at?

Totally valid concern to raise early - but I'd hold off on assuming anything about the TX power until you've pulled the actual datasheet or contacted the supplier directly, because "50km" marketing claims on BLE modules are almost always tied to specific antenna configs, line-of-sight conditions, and sometimes proprietary long-range modes (like Coded PHY) rather than just raw output power alone. I've seen similar specs quoted at anywhere from +10 to +20dBm depending on the chipset underneath, so the regulatory question really does hinge on which chip they're actually using. Worth firing off a direct question to RFOXiA support before you go too far down the prototype path.

@Barbara Jackson yeah the previous reply gave you solid general advice, but I can add a bit more specific context here since I've been following RFOXiA's stuff pretty closely.

 

The 50km figure is the drone-to-drone number specifically — that's both modules airborne, which eliminates ground reflections and multipath that would otherwise kill your link budget. Ground-to-ground is 5km and man-to-drone is 15-20km, so the conditions matter a lot for what you'll actually see in your application.

 

On the TX power question — the module is FCC certified, which is the key thing to know here. FCC certification means it's already been tested and approved for legal operation in the US, so if you're building stateside you're covered out of the box. That said, the specific output power and chipset details, yeah I'd reach out to RFOXiA directly through the Dev Hub or their support — they've been pretty responsive from what I've seen in the community, and for a telemetry build where you're actually relying on that link margin, you want the exact spec sheet numbers rather than guessing from forum posts.

 

What kind of telemetry are you running? That'll also affect whether the 2Mbps data rate is relevant to your use case or if you're more concerned purely with range at low throughput.

Patricia's spot on about the Coded PHY angle - that Long Range mode can get you serious distance gains without cranking TX power, so the 50km claim might be less about raw wattage and more about PHY configuration and antenna gain stacked together. If you can find out which chipset is underneath (Nordic nRF52 series is a common candidate for this kind of spec) you'll have a much clearer picture of the power ceiling and what regs apply. Def worth a direct ask to RFOXiA support before assuming worst case.

Both points about Coded PHY are solid - just want to add that if it is Nordic underneath, the nRF52840 tops out at +8dBm native and you'd need an external PA to even get close to +20dBm territory, so that's a useful ceiling to sanity-check against while you wait on RFOXiA to respond. Either way, 50km LOS with good antenna gain and Coded PHY is at least plausible without necessarily tripping regional regs, but yeah, get the actual chipset confirmed before you assume anything.

Good thread - one more thing worth checking once you get the datasheet is whether there's an onboard PA and whether it's enabled by default or needs explicit config, because some modules ship with the PA technically available but conservative defaults in firmware, so your actual out-of-box TX power might be lower than the headline spec anyway. That could actually work in your favour from a regulatory standpoint while you're still prototyping.

Jumping in late but just to add a practical note - if you do end up with an external PA in the chain, make sure you're also checking the duty cycle regs for your region, not just the power ceiling, because some jurisdictions that are fine with the TX power will still bite you on continuous transmission limits at those levels. Get the datasheet confirmed first obviously, but worth having that in your back pocket for the reg review.

Hey, just to add some visibility here - I've flagged this thread internally and we'll get someone to pull the confirmed chipset and TX power spec for the MultiNav Pro+ so you've got something concrete to work with rather than educated guesses. Should have a proper answer for you early next week, but in the meantime the points raised about Coded PHY and default PA config are exactly the right things to be thinking about.

Good to see Richard flagged it internally - while you're waiting on that confirmed spec, it's worth pulling up the link budget math yourself with a few assumed TX power scenarios (+8dBm vs +20dBm) so you've already got your regulatory headroom mapped out before the datasheet lands. Saves you a round trip once you have the real numbers.

Seconding Joseph's suggestion on the link budget math - even just running the numbers at both ends of the likely TX power range now means when Richard's team comes back with the confirmed spec you're basically just plugging in one variable and you're done. Saves a lot of back-and-forth once the datasheet lands.

Seconding the link budget prep advice - and while you're at it, if you haven't already grabbed the nRF5340 or similar Coded PHY datasheets just to have the PA config tables handy, that'll make it way easier to sanity check whatever Richard's team comes back with against actual chipset limits rather than just taking the spec sheet number at face value.

Solid thread already - one thing worth adding while you're doing that link budget prep, don't forget to factor in antenna gain on both ends because that's often where the 50km headline number gets its "help" on paper, and knowing whether that spec assumes an ideal isotropic or a real-world directional antenna will matter a lot for your regulatory calc too.

Curtis nails it on the antenna gain point - the 50km figure almost certainly assumes high-gain directional antennas at both ends, which is basically a best-case lab/field scenario, so your real-world link budget with omnidirectional antennas is gonna look pretty different. Definitely worth modelling both cases before you commit to a form factor.