Cellular Gateway · Volume 2
The GL-X3000 Spitz AX in Detail
Introduction
The GL.iNet GL-X3000, marketed as the Spitz AX, is a dual-SIM 5G cellular gateway aimed at recreational vehicles, rural fixed-wireless, and mobile deployments. It sits in a useful gap in the market: substantially more capable than a consumer hotspot, substantially cheaper than the Peplink hardware that dominates professional mobile installations, and running OpenWrt underneath a friendly interface, which matters to anyone who wants to configure it rather than accept it.
This volume is the hardware assessment. The verdict on whether to buy it is deferred to volume five; what follows is what the thing actually is.
2.1 Specifications that matter
Table 1 — Specifications that matter
| Property | Value |
|---|---|
| Processor | MediaTek MT7981A, dual-core, 1.3 GHz |
| Memory | 512 MB DDR4 |
| Storage | 8 GB eMMC |
| Cellular modem | Quectel RM520N-GL (5G NR sub-6) — an LTE-only variant with the EM160R-GL Cat-16 modem also exists |
| Cellular antenna ports | 4 × SMA-female, specified 600 MHz – 6 GHz, labelled MAIN, DIV/GNSS, MIMO 1, MIMO 2 |
| Wi-Fi | 802.11ax dual-band, 574 Mbps (2.4 GHz) + 2402 Mbps (5 GHz) |
| Wi-Fi antenna ports | 2 × RP-SMA-female, plus an internal 5 GHz antenna |
| Wired | 1 × 2.5 Gb WAN, 1 × 1 Gb LAN, USB |
| SIM | 2 × nano-SIM with automatic failover |
| GNSS | GPS, GLONASS, BeiDou, Galileo, QZSS |
| Power | DC barrel, 12 V / 2.5 A nominal, accepts 9–36 V; under 14 W |
| Operating temperature | 0 – 40 °C |
| Size and weight | 155 × 95 × 36 mm, 520 g |
| Price | about $380 for the 5G version |
Three of those lines deserve more than a table row.
2.2 The modem is the reason to buy this box
The RM520N-GL is a serious module, and it is the single most important component in the decision. Its band support is unusually complete for a device at this price, and specifically it includes the bands that matter in the rural Upper Peninsula rather than the ones that produce good speed-test screenshots in cities.
The relevant coverage bands are the low-band allocations, because low frequencies diffract around terrain and penetrate foliage in a way mid-band simply does not. The module covers n71 and LTE B71 (600 MHz, T-Mobile), B12 and B13 (700 MHz, AT&T and Verizon), B14, B26 and n26 (850 MHz), and B5 and B8. It also covers n41 (2.5 GHz) for throughput where mid-band 5G exists, and the C-band and other mid/high allocations up to n79.
The practical translation: in the Keweenaw, the connection that will or will not exist is almost certainly on 600 or 700 MHz, and this modem receives all of them. That is not something a cheaper Cat-4 gateway can claim, and it is the difference between a router that is theoretically capable and one that is capable in this specific terrain.
The module supports downlink 4×4 MIMO on selected bands, which is what the four antenna ports are for and is the subject of volume three.
2.3 The power and temperature envelope
Under 14 W with a 9–36 V input range is close to ideal for a truck. It runs directly from vehicle 12 V with no inverter, tolerates the voltage sag of cranking and the rise of a charging system without complaint, and adds a negligible load beside a fridge. On a fused, Anderson-connectored distribution bus of the kind planned for this build, it is a rounding error.
The 0 – 40 °C operating specification is the real constraint, and it is a genuine problem for Michigan. A truck parked overnight in the Keweenaw in October is below freezing, and in winter it is far below. The device is specified to operate from freezing upward. In practice consumer electronics with commercial-grade temperature ratings usually survive well below their rated minimum — the specification is a warranty boundary as much as a physical one — but “usually survives” is not a design basis. If the gateway is expected to work on cold-season trips, it should live inside the cab or inside an insulated drawer rather than in the bed, which in turn shortens the coax run and is convenient anyway.
The upper bound deserves a thought too: a sealed case in direct summer sun in a truck bed reaches well past 40 °C.
2.4 OpenWrt underneath, and what that is worth
GL.iNet ships its own management interface over OpenWrt, with the underlying LuCI available. For this build that matters in specific ways rather than as a general virtue:
- WireGuard and OpenVPN clients and servers are built in, so the rig can reach home services or route traffic through a home connection.
- Multi-WAN with failover and load balancing across the two SIMs, the 2.5 Gb Ethernet WAN, and Wi-Fi-as-WAN. The Wi-Fi-as-WAN path is genuinely useful in an overlanding context: a campground or town café connection can be adopted as the uplink while the whole rig’s devices stay on their usual network with no reconfiguration.
- Real band locking and cell selection, exposed through AT commands to the modem. In fringe conditions this is not a nicety. Modems left to themselves will frequently prefer a mid-band 5G cell with a strong-looking indicator and a useless data path over a low-band LTE cell that would actually work. The ability to force B12 or B71 and stay there is one of the strongest arguments for a gateway over a hotspot.
- Persistent signal metrics — RSRP, RSRQ, SINR, serving cell and band — which turn antenna aiming from guesswork into measurement. Volume three depends on this.
2.5 Where it is weaker than the professional alternatives
Honesty requires the other column. Against a Peplink BR1 Pro 5G, which is the obvious step up at roughly two to three times the price:
- SpeedFusion bonding is absent. Peplink can bond multiple cellular connections into one aggregate session that survives the loss of any single link mid-stream. The GL-X3000 fails over between SIMs, which drops sessions.
- Certification and support are thinner. GL.iNet’s firmware moves quickly and occasionally regresses; the community forum is the support channel in practice.
- The two SIMs are not simultaneous. Dual-SIM here means one active with automatic failover to the other, not two concurrent radios. Failover takes tens of seconds and is not seamless. A rig that genuinely needs two carriers at once needs two modems.
- Vibration and ingress ratings are not vehicle-grade. It is a plastic-cased indoor device being asked to live in a truck.
None of these is disqualifying for a personal overland rig. All of them would matter in a commercial fleet, which is roughly the boundary between this product and Peplink’s.
2.6 The Wi-Fi gotcha worth knowing before installing
GL.iNet’s own staff have clarified on their forum that the unit has an internal 5 GHz Wi-Fi antenna in addition to the two external RP-SMA ports. The implication for a vehicle install is counter-intuitive: if the two external Wi-Fi antennas are relocated outside the vehicle along with the cellular antennas, the in-cab Wi-Fi loses its 2×2 MIMO and performance inside the truck degrades — the opposite of the intent.
Move the cellular antennas outside; leave the Wi-Fi antennas on the box, inside. If coverage is wanted at a camp table thirty feet away, the correct answer is a second inexpensive access point wired to the LAN port, not exterior Wi-Fi antennas.
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