Helium Hotspot Connections

Have a ques­tion about which con­nec­tor or pow­er sup­ply or anten­na cable you should get? Here’s an easy ref­er­ence to use when you’re order­ing parts. I make every effort to keep this updat­ed, but in some cas­es the man­u­fac­tur­ers them­selves are con­tra­dic­to­ry. Check YOUR hotspot to make sure you’re get­ting the right con­nec­tor and PoE injec­tors. Most hotspots are fine with an 802.3af, or “active” PoE injector/splitter com­bo. Check your Hotspot care­ful­ly to make sure you’re get­ting the right sized plug at the split­ter end; USB‑C or a spe­cif­ic size of bar­rel plug 5.5 x 2.1 or 2.5 etc.

Man­u­fac­tersRF Con­nec­torPow­er Sup­plies and PoE AdaptersMfr LinkPoE Injec­torPoE Split­ter
NEBRA HNT Out­door Hotspot MinerN‑Type Female802.3AF 48V POE, or use 9–16V DC @ 15W, DC Bar­rel Jack — 2MM Pin, 6.5MM Bar­rel cen­tre pos­i­tive. Rec­om­mend­ed PSU 12V @1.5ASpecs HerePoE Injec­tor
NEBRA HNT Indoor Hotspot MinerRP-SMA FemaleDC Bar­rel Jack 6.5 x 2.0 mm, 12V 1.5A. PoE split­ter optionSpecs HerePoE Injec­tor
Bob­cat MinerRP-SMA FemalePow­er via DC 12V or PoE Split­ter Option — Bar­rel Jack 12V 5.5X2.1mm Specs HerePoE Injec­torPoE Split­ter
RAK v2 Hotspot MinerRP-SMA FemaleUSB‑C Pow­er Sup­ply or PoE Split­ter Option — Type C 5V GigabitSpecs HerePoE Injec­torPoE Split­ter
SyncroB.it HNT GatewayRP-SMA Female2.5mm, 12 Volt Pow­er Jack Option or — Pas­sive PoE (12–55 volts)Specs HerePoE Injec­tor
OG Heli­um HotspotRP-SMA FemalePow­er via DC5V or PoE Split­ter Option — Bar­rel Jack 5V 3Amps 5.5X2.1mmPoE Injec­torPoE Split­ter
RAK v1 Hotspot MinerRP-SMA FemaleUSB‑C Pow­er Sup­ply or — PoE Split­ter Option — Type C 5V GigabitPoE Injec­torPoE Split­ter
Lon­gAPSMA FemaleBar­rel Jack 12V 2A 5.5X2.5mmPoE Injec­torPoE Split­ter
Lon­gAP ProN‑Type FemalePoE 802.3at Specs HerePoE Injec­tor
Lon­gAP LightRP-SMA FemalePoE 802.3af, Bar­rel Jack 12V 1A 5.5X2.1mm (to be finalized)Specs HerePoE Injec­torPoE Split­ter
Sense­CAP M1RP-SMA FemaleUSB C, DC 5v 3ASpecs HerePoE Injec­torPoE Split­ter

As you’ll see, most of the pro­duc­tion min­ers use an RP-SMA con­nec­tion. That means the cable you’ll want to order if you’re installing an after­mar­ket anten­na will be RP-SMA male <–> (usu­al­ly) N‑type male.

Want to dive deep­er, check out some pic­tures, and learn a lit­tle more? Here we go!

RP-SMA stands for Reverse Polar­i­ty SubMinia­ture ver­sion A). The RP series were designed to stop you from con­nect­ing an “unau­tho­rized anten­na” to your gear, whether that’s a Heli­um hotspot or any radio. The FCC’s thought process was along the lines of, “all man­u­fac­tur­ers will have RP-SMA so you can only con­nect them to RP-SMA capa­ble anten­nas, and nobody will sell RP-SMA con­nec­tors to con­sumers.” Pri­or to the inter­net mak­ing all infor­ma­tion and parts avail­able to every­one, that method worked well enough. Now, it’s just con­fus­ing. Onward!

Female RP-SMA con­nec­tors have a female con­tact body (ground) and a male inner pin con­tact (sig­nal). A male RP-SMA con­nec­tor is the oppo­site in both respects — male body (inside threads) with a female inner sleeve contact. 

Here are all four con­nec­tor types. You’ll also see the female referred to as an “jack”, and the male referred to as “plug”. Slight­ly con­fus­ing, right?

SMA and RPSMA Male and Female Connections

Next up: N‑Type Connections

Ok, that’s the con­fus­ing stuff out of the way. Here is what you’ll typ­i­cal­ly see when con­nect­ing to an after­mar­ket anten­na. These are called N‑type con­nec­tions, and are larg­er in size the the SMA series.

Ok, that should clear up most of the ques­tions sur­round­ing what cable con­nec­tion you have, and what you should get. If you have ques­tions about cable loss, check out this post on it, or for quick ref­er­ence, this table: 


Length of CableLMR 195LMR 240LMR 400LMR 600LMR 900
5 Feet0.
20 Feet2.
50 Feet5.
75 Feet7.
100 Feet10.

If you’d like to go beyond just con­nect­ing some cables, there are a ton of learn­ing options on this site.

I’ve built cours­es on Heli­um and Heli­umVi­sion, offer trou­bleshoot­ing ses­sions, as well as cus­tom con­sult­ing to indi­vid­ual clients. I dive into strat­e­gy, indi­vid­ual hotspot opti­miza­tion, and help­ing you under­stand where you can pros­per in the Heli­um ecosystem. 

Rock on!