# SC Robotics — Comms Node BOM Research (900MHz HaLow + 1.3GHz/3.4GHz Long-Range Leg)
Researched 2026-08-17. All prices are snapshot quotes from the cited retailer at time of writing; SDR/RF hobbyist and amateur-radio component pricing fluctuates and stock varies — re-verify before ordering. Quantities assume **2 units per link** (rover side + base station side) unless noted otherwise.
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## 1. 900MHz Wi-Fi HaLow Leg (OpenMANET-style build — design locked)
Per the [OpenMANET project](https://openmanet.github.io/docs/hardware/raspberry-pi), the reference build is a Raspberry Pi + Morse Micro HaLow HAT running OpenWrt with 802.11s + batman-adv. OpenMANET's hardware table explicitly lists the **"Seeed WM1302 + Wio-WM6108"** combo as the common setup, and separately documents an all-in-one alternative from AsiaRF.
### Option A — Seeed 2-piece combo (cheapest, matches OpenMANET's documented setup)
| Item | Price | Source |
|---|---|---|
| Raspberry Pi 4 Model B (4GB) | $60–$100 (retailer/allocation dependent; RPi Foundation's own product brief lists $100 official MSRP for 4GB; some retailers/allocations run $55–60; Adafruit currently sells at $120) | [raspberrypi.com](https://www.raspberrypi.com/products/raspberry-pi-4-model-b/), [RPi 4 product brief PDF](https://pip-assets.raspberrypi.com/categories/545-raspberry-pi-4-model-b/documents/RP-008344-DS-5-raspberry-pi-4-product-brief.pdf), [Adafruit](https://www.adafruit.com/product/4296) |
| Seeed WM1302 Pi HAT (mini-PCIe carrier board) | $19.90–$21.99 | [Seeed Studio](https://www.seeedstudio.com/WM1302-Pi-Hat-p-4897.html), [RobotShop](https://www.robotshop.com/products/seeedstudio-wm1302-lorawan-raspberry-pi-hat) |
| Seeed Wio-WM6108 Wi-Fi HaLow mini-PCIe module (Quectel FGH100M-H, Morse Micro MM6108, US 902–928MHz, SPI) | $14.99 | [Seeed Studio](https://www.seeedstudio.com/Wio-WM6108-Wi-Fi-HaLow-mini-PCIe-Module-p-6394.html) |
| 2.6dBi Long Range Antenna, SMA male, 915MHz, 195mm | $2.49 | [Seeed Studio](https://www.seeedstudio.com/External-Antenna-915MHZ-2-6dBi-SMA-L195mm-p-5047.html) |
| SMA-to-I-PEX antenna cable, 120mm | $1.90 | [Seeed Studio](https://www.seeedstudio.com/Wio-WM6108-Wi-Fi-HaLow-mini-PCIe-Module-p-6394.html) (bundled on same page) |
| microSD card, 32GB (A1-rated) | ~$9 (typical current street price; not separately re-verified this session) | — |
| Official RPi USB-C 5V/3A power supply | ~$8 (typical current street price; not separately re-verified this session) | — |
| Sixfab IP65 outdoor project enclosure (fits Pi + stacked HAT) | $69.00 | [Sixfab](https://sixfab.com/product/raspberry-pi-ip65-outdoor-iot-project-enclosure/) |
| **Subtotal per node** | **≈ $185–$226** | |
| **× 2 nodes (rover + base)** | **≈ $371–$452** | |
Note: Seeed's own setup guide explicitly recommends buying the 2.6dBi antenna + SMA-to-I-PEX cable alongside the WM6108 module, confirming this is the intended accessory pairing. ([Seeed wiki](https://wiki.seeedstudio.com/getting_started_with_wifi_halow_mini_pcie_module/))
### Option B — AsiaRF all-in-one HAT (simpler assembly, no separate carrier+module)
| Item | Price | Source |
|---|---|---|
| AsiaRF MM610X-H06-1 Wi-Fi HaLow Raspberry Pi HAT (Morse Micro MM6108, integrated, US-band variant) | $99.00–$135.00 (listing shows both figures) | [AsiaRF](https://asiarf.com/product/wi-fi-halow-raspberry-pi-hat-module-mm610x-h06/), [Morse Micro community forum confirming AsiaRF as OpenMANET-supported hardware](https://community.morsemicro.com/t/halow-support-for-eu-region/829) |
| Raspberry Pi 4B (4GB) + antenna + cable + SD + PSU + enclosure (same as above) | ≈ $115–$126 | (as above) |
| **Subtotal per node** | **≈ $214–$261** | |
| **× 2 nodes** | **≈ $428–$522** | |
**Recommendation:** Option A (Seeed combo) is cheaper and is the exact hardware OpenMANET's own docs reference — go with that unless the two-board mini-PCIe assembly proves fragile in a vibration/off-road environment, in which case the single-board AsiaRF HAT is the more rugged pick.
---
## 2. 1.3GHz Leg — Path (a): Homemade SDR Build (23cm amateur band, 1240–1300MHz)
This path needs: SDR transceiver, power amplifier (SDR boards output milliwatts, need PA to reach useful range), bandpass filter (to clean harmonics before the antenna, especially with non-linear-clean PA stages), 23cm antenna, a compute host to run GNU Radio, and RF cabling/connectors.
### SDR board (choose one)
| Item | Price | Notes | Source |
|---|---|---|---|
| Analog Devices ADALM-PLUTO (PlutoSDR), 325MHz–3.8GHz, covers 1.3GHz natively | $243.73–$294.24 (varies by distributor) | Official ADI/Analog Devices educational SDR; half/full-duplex, 20MHz BW, USB-powered | [Richardson RFPD](https://shop.richardsonrfpd.com/Products/Product/ADALM-PLUTO) ($243.73), [Newark](https://www.newark.com/analog-devices/adalm-pluto/learning-module-plutosdr-3-8ghz/dp/49AK8158) ($294.24) |
| LimeSDR Mini 2.0, 10MHz–3.5GHz, 40MHz BW, 1x1 | $600.00 (current-gen; original 1.0/399 pricing discontinued) | Pricier since the 2.0 hardware refresh; also covers 1.3GHz | [CrowdSupply (official)](https://www.crowdsupply.com/lime-micro/limesdr-mini-2) |
PlutoSDR is the clear budget pick and is well-supported in GNU Radio; LimeSDR Mini 2.0 costs 2.5x more for wider bandwidth/2x2 MIMO the team likely doesn't need for a point-to-point control/telemetry link.
### Power amplifier (1240–1300MHz / 23cm band) — choose one path
| Item | Price | Notes | Source |
|---|---|---|---|
| **DIY/cheap:** Mitsubishi M57762 bare PA module (18W out, 1240–1300MHz, 12.5V, SMA-less — needs driver/bias circuit and heatsink) | $68.21 (1pc) | Requires building a driver/bias PCB (MMIC driver, decoupling, heatsink) — not turnkey; add ~$30–50 in supporting parts/heatsink | [rf-microwave.com](https://www.rf-microwave.com/en/mitsubishi/m57762/uhf-power-amplifier-module/m57762/) |
| **Turnkey:** Kuhne Electronic MKU PA 23CM-50W B (1240–1300MHz, 50W CW, SMA in/out, milled aluminum case, ready to use) | €545.01 incl. VAT / €457.99 net (≈ $495–$590 USD depending on FX and import duty) | Plug-and-play amateur-radio-grade amplifier; needs a separate 28V supply | [Kuhne Electronic shop](https://shop.kuhne-electronic.com/kuhne/en/shop/power-amplifiers/MKU+PA+23CM50W+B++Power+Amplifier/?card=2133) |
Given this is a student competition build with limited RF assembly time, the DIY M57762 path is far cheaper but adds real engineering risk (matching, decoupling, thermal design) — factor that into the "homemade SDR" decision versus the off-the-shelf path (b) below.
### Bandpass filter (clean PA output / protect receiver)
| Item | Price | Notes | Source |
|---|---|---|---|
| Mini-Circuits CBP-A1230C+ ceramic resonator bandpass filter, 1160–1300MHz, SMA, 50Ω | $39.02 (1–9 qty) | Matches the 23cm band; needed especially with the non-turnkey M57762 path where harmonic suppression isn't otherwise guaranteed | [Mini-Circuits](https://www.minicircuits.com/WebStore/modelSearch.html?model=CBP-A1230C%2B) |
### Antenna (23cm / 1.3GHz)
| Item | Price | Notes | Source |
|---|---|---|---|
| Comet CYA-1216E, 16-element Yagi, 1240–1300MHz, 16dBi, N-female, 100W rated | $207.95 | Directional — good for a fixed base-station-to-rover link if rover antenna can stay roughly pointed, or if omnidirectional coverage isn't required | [DX Engineering](https://www.dxengineering.com/parts/cma-cya-1216e) |
(Lower-gain/lower-cost omni antennas for 23cm are less common commercially than for 900MHz — this band is dominated by ham-radio Yagi/dish gear. If omni coverage matters more than gain, budget extra research time here.)
### Compute host (run GNU Radio flowgraph / interface to Pluto/Lime)
| Item | Price | Notes |
|---|---|---|
| Raspberry Pi 4 Model B (4GB) — reuse same pricing as HaLow leg | $60–$100 | Team already standardizing on Pi 4 for the HaLow leg; reusing here keeps the toolchain consistent. A laptop already on the team could substitute at $0 incremental cost for early bench testing. |
### Connectors/cabling
| Item | Price | Notes | Source |
|---|---|---|---|
| SMA male-to-male RG178 coax cable, 1ft | $11.58 | For SDR→filter→PA jumpers | [coaxrf.com](https://www.coaxrf.com/cables/rg178/sma-male-to-sma-male) |
| N-to-SMA adapters (PA has N connectors, filter/SDR use SMA) | ~$8–15/each (widely available, e.g. Amazon/Mouser; not independently re-priced this session — budget ~$30 for a full set) | Needed to bridge PA's N-type connectors to SMA elsewhere in the chain | — |
### Path (a) cost rollup — per node
| Configuration | SDR | PA | Filter | Antenna | Compute | Cables/adapters | **Total/node** |
|---|---|---|---|---|---|---|---|
| Budget (Pluto + DIY M57762 PA) | $244–294 | $68 + ~$40 support parts | $39 | $208 | $60–100 | ~$42 | **≈ $700–$790** |
| Turnkey (Pluto + Kuhne PA) | $244–294 | ~$495–590 | $39 | $208 | $60–100 | ~$42 | **≈ $1,150–$1,270** |
**× 2 nodes:** Budget ≈ **$1,400–$1,580** · Turnkey ≈ **$2,300–$2,540**
---
## 3. 1.3GHz Leg — Path (b): Off-the-Shelf 3.4GHz Commercial Radio (alternative band/hardware)
Ubiquiti is the practical commercial option in this frequency range; MikroTik does not have a comparable dedicated 3.3–3.9GHz product line (their portfolio concentrates on 2.4/5GHz ISM and separately licensed bands via different hardware). Two Ubiquiti tiers exist:
### Budget tier — Rocket M365 (3.65GHz, US/FCC-legal band)
| Item | Price | Notes | Source |
|---|---|---|---|
| Ubiquiti Rocket M365 radio (3.65GHz, 2x2 MIMO, US/FCC channel plan) | $189.00–$249.99 | Listed EOL by some distributors ("no direct replacement") — check current stock before committing | [Microcom](https://www.microcom.us/rocketm365.html) ($189), [WLANmall](https://www.wlanmall.com/ubiquiti-3-65-ghz-wireless-bridge-rocketm365-us/) ($191.40), [Amazon](https://www.amazon.com/Ubiquiti-Rocket-M365-Wireless-ROCKETM365/dp/B00KDMDPZC) ($249.99) |
| Ubiquiti RocketDish RD-3G26 (3.35–3.75GHz, 26dBi, 650mm dish, mates with Rocket M365/airFiber radios) | $281.02 | Required companion antenna — Rocket M365 has no integrated antenna | [Ubiquiti reseller pricelist](https://www.amerisponse.com/Ubiquiti-Networks/Ubiquiti-Networks-Pricelist.html) |
| **Subtotal per node** | **≈ $470–$531** | |
| **× 2 nodes** | **≈ $940–$1,062** | |
### Premium tier — airFiber AF-3X (3.3–3.9GHz, carrier-grade PtP, ~200km rated range, GPS-synced)
| Item | Price | Notes | Source |
|---|---|---|---|
| Ubiquiti airFiber AF-3X radio (500+ Mbps, priced **per side** — 2 required per link) | $799.00 (MSRP, consistent across Microcom/RoweWireless/BalticNetworks; one reseller listed $1,069.99) | [Microcom](https://www.microcom.us/af3x.html), [Rowe Wireless](https://www.rowewireless.com/3ghz-airfiberx-ptp-500mbps-radio/), [Baltic Networks](https://www.balticnetworks.com/products/ubiquiti-3ghz-airfiberx-ptp-500mbps-radio-us-af-3x-us) |
| Ubiquiti AF-3G26-S45 antenna (3.3–3.8GHz, 26dBi, 650mm, required companion for AF-3X) | $299.00 | [ispsupplies.com](https://www.ispsupplies.com/Ubiquiti-airFiber-X-AF-3G26-S45-3GHz-26-dBi-airFiber-X-Antenna) |
| **Subtotal per node** | **$1,098.00** | |
| **× 2 nodes** | **$2,196.00** | |
### Important caveats for Path (b)
1. **Both dishes are large and narrow-beam** (650mm diameter, 7° beamwidth). That's fine for a fixed base-station-to-fixed-relay link but is a poor fit for a link where one end (the rover) moves and the antenna needs to stay pointed — this would need either a tracking mount, a lower-gain/wider-beam antenna substitute, or accepting the base station re-aims manually as the rover moves within a small operating area. Flag this to whoever resolves the (a)-vs-(b) decision — it may be a bigger practical blocker than price.
2. **Licensing:** the 3.3–3.9GHz band is *not* license-exempt ISM in the US. Ubiquiti's own product pages note "a license may be required in some regions," and the Rocket M365 datasheet explicitly states the 3/3.65GHz band "requires a license" in the US (Part 90 / FCC ULS or similar). This contrasts with the license-exempt 900MHz HaLow leg and is a real logistical hurdle for a student team — worth checking with team advisors/mentors before committing budget here, or exploring whether the amateur 23cm band (path a) is actually the lower-friction regulatory choice since it only requires an FCC Technician-class ham license held by an operator, not a per-link authorization.
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## Cost Summary
| Build | Configuration | Cost per node | **Total (2 nodes)** |
|---|---|---|---|
| **900MHz HaLow** | Option A (Seeed WM1302 + Wio-WM6108 combo) | $185–$226 | **$371–$452** |
| 900MHz HaLow | Option B (AsiaRF all-in-one HAT) | $214–$261 | $428–$522 |
| **1.3GHz — Path (a) SDR** | Budget (PlutoSDR + DIY M57762 PA) | $700–$790 | **$1,400–$1,580** |
| 1.3GHz — Path (a) SDR | Turnkey (PlutoSDR + Kuhne 50W PA) | $1,150–$1,270 | $2,300–$2,540 |
| **1.3GHz/3.4GHz — Path (b) COTS** | Budget (Ubiquiti Rocket M365 + dish) | $470–$531 | **$940–$1,062** |
| 1.3GHz/3.4GHz — Path (b) COTS | Premium (Ubiquiti airFiber AF-3X + dish) | $1,098 | $2,196 |
### Grand totals by scenario (900MHz leg + one long-range leg)
| Scenario | Total (both legs, 2 nodes each) |
|---|---|
| HaLow (A) + SDR budget (a) | **≈ $1,771–$2,032** |
| HaLow (A) + SDR turnkey (a) | ≈ $2,671–$2,992 |
| HaLow (A) + Ubiquiti Rocket M365 (b) | **≈ $1,311–$1,514** |
| HaLow (A) + Ubiquiti airFiber AF-3X (b) | ≈ $2,567–$2,648 |
**Cheapest overall path:** HaLow + Ubiquiti Rocket M365 budget tier (≈$1,300–$1,500 total), but carries the licensing question above and the fixed-dish/moving-rover pointing problem. **Cheapest SDR-native path** (if the team wants full homebrew control over the RF chain, or the licensing story favors amateur radio) is HaLow + PlutoSDR/M57762 DIY (≈$1,770–$2,030), with the tradeoff of real RF assembly/tuning risk on the PA driver stage.
---
## Notes on sourcing confidence
- All prices above were pulled from live retailer/manufacturer pages in this research session (2026-08-17) via web search; no scraping of cached/stale price aggregators was used as a primary source where a direct manufacturer/reseller price was available.
- Raspberry Pi 4B pricing has a wide spread across sources due to ongoing allocation/supply constraints — budget toward the higher end ($100–120) to avoid a shortfall if the low-end price isn't available at order time.
- The Wio-WM6108 module was flagged "Discontinued" on one UK reseller (The Pi Hut) but is in-stock direct from Seeed Studio and multiple other resellers (Pakronics, Comet Electronics) — verify stock at order time given the discontinuation flag.
- PA and antenna pricing for the 23cm amateur band comes from ham-radio specialty retailers (Kuhne, DX Engineering, Mini-Circuits, rf-microwave.com) rather than mainstream electronics distributors — these are legitimate, established RF suppliers but typically have longer lead times and less aggressive competition on price than consumer electronics.