OmniSDR

your click-and-tune multi-band panadapter

SDR Station overview

This station runs six SDR endpoints off three independent receive chains (HF/VHF/UHF) sharing one Docker multicast bus. OmniSDR (below) is the multi-band panadapter; the others are single-purpose UIs for the same underlying receivers.

Full station technical documentation — architecture, switching, radio, power, and hardware detail beyond what's on this page — is available at the full documentation page.

Service	Band	What it is
UberSDR	HF	Production per-band audio tuner UI.
OmniSDR	Multi-band	Click-and-tune spectrum panadapter — this page's subject, see below.
UberSDR Multi dev/test	VHF + UHF	Same UI as UberSDR, extended to VHF/UHF. Not production — may be down.
HF	HF	Lightweight single-band UI.
UHF	UHF (70cm)	Lightweight single-band UI.
VHF	VHF (2m)	Lightweight single-band UI.

From the Internet

OmniSDR drives the companion UberSDR session — click a signal on the spectrum and the UberSDR tab tunes there. The marker follows UberSDR's dial in both directions.

From your LAN (running your own instance)

OmniSDR can tune any device on your LAN — UberSDR plus auto-discovered rigctld rigs. Pick the active ones in Right-click → Targets ▸; ticked targets tune in parallel.

Markers: amber = UberSDR · cyan = local rig.

Right-click menu

• Layouts ▸ — pick a preset; Manage Layouts… for the band grid
• Options ▸ — viewing toggles
• Targets ▸ — which devices receive tunes (LAN only)

Shortcuts

F fullscreen · Esc close · Right-click menu

Scope gating — public viewers can't drive local rigs

Hardware & stack on the UberSDR host

Read bottom-up: physical hardware on the floor, apps on top. Every layer consumes from the layer beneath it. Three independent receive chains (HF/VHF/UHF) share one Docker multicast bus.

┌──────────────────────────────────────────────────────────────────────────┐
│                      UberSDR host  (192.168.36.38)                       │
│                                                                          │
│  ┌────────────────────────────────────────────────────────────────┐      │
│  │  Apps (consume the multicast bus, none talk USB directly)      │      │
│  │   • ka9q_ubersdr      — HF audio UI (production)               │      │
│  │   • omnisdr           — multi-band spectrum + tune dispatcher  │      │
│  │   • ka9q_ubersdr_dev  — VHF+UHF audio UI (dev/test build)      │      │
│  │   • ka9q-web-uhf      — lightweight single-band UHF UI         │      │
│  │   • ka9q-web-vhf      — lightweight single-band VHF UI         │      │
│  └───────────────────────────────▲────────────────────────────────┘      │
│                                  │ multicast                             │
│  ┌───────────────────────────────┴───────────────────────────────┐       │
│  │   sdr-network  (Docker bridge — control + I/Q + spectrum)     │       │
│  └───────────────────────────────▲───────────────────────────────┘       │
│                                  │                                       │
│  ┌───────────────────────────────┴───────────────────────────────┐       │
│  │  radiod instances (each owns one SDR, runs the FFTs)          │       │
│  │   • ka9q-radio   (HF)   — custom fork, feeds off RX888 below  │       │
│  │   • radiod-vhf   (VHF)  — upstream, feeds off RTL-SDR Blog V4 │       │
│  │   • radiod-uhf   (UHF)  — upstream, feeds off Airspy R2       │       │
│  └───────────────────────────────▲───────────────────────────────┘       │
│                                  │ ① USB-3 in  (host port)               │
│                                  │    data + bus power (HF chain         │
│                                  │    shown below; VHF/UHF SDRs          │
│                                  │    are plain USB, no Y-cable)         │
│              ┌───────────────────┴────────────────────┐                  │
│              │  Y USB-3 cable — 3-port junction        │                 │
│  5 V PSU ────┤  ② USB 5 V in  (extra power, no data)   │                 │
│              └───────────────────▲────────────────────┘                  │
│                                  │ ③ USB-3 + 5 V out                     │
│                                  │    data + combined power              │
│                          ┌───────┴────────┐                              │
│                          │  RX888 mk2     │  vendor: 5 V / 2 A;          │
│                          │  wideband HF   │  >1 A typical, ~1.5 A peak   │
│                          │  SDR (USB 3)   │  vs USB-3 nominal 900 mA     │
│                          └────────────────┘                              │
└──────────────────────────────────────────────────────────────────────────┘

Layer	What sits here	Why
Hardware (HF)	RX888 mk2 on USB 3, attached via a Y USB-3 cable (3-port junction: ① USB-3 in from host, ② USB 5 V in from a wall PSU, ③ USB-3 + combined 5 V out to the RX888)	The wideband HF radio. Single, exclusive to ka9q-radio. The vendor rates the device at 5 V / 2 A (≈10 W); the related Web-888 draws more than 1 A typical with peaks around 1.5 A (Web-888 power guide), and community measurements on the Mk2 USB confirm the same range (NextGenSDRs thread). That's well above the 900 mA a single USB-3 port nominally provides, so the Y cable's port ② injects supplemental 5 V from a separate source on top of the host-port bus power coming in on ①. Current scales with sample rate, which also drives the thermal load (KA7OEI on RX-888 thermals).
Hardware (VHF)	RTL-SDR Blog V4 on plain USB 2 — no Y-cable, no supplemental power needed	2 m receiver, exclusive to radiod-vhf.
Hardware (UHF)	Airspy R2 on plain USB 2 — no Y-cable, no supplemental power needed	70 cm receiver, exclusive to radiod-uhf.
Radio backend	ka9q-radio (HF), radiod-vhf, radiod-uhf	Each owns one SDR, runs the FFTs, exposes everything else via multicast.
Bus	sdr-network Docker bridge multicast	One pipe for control, I/Q channels, and spectrum. Containers join this bridge to talk to the radios without going through host networking.
Apps	ka9q_ubersdr & omnisdr (production); ka9q_ubersdr_dev, ka9q-web-uhf, ka9q-web-vhf (dev/test or lightweight single-band)	All consume from the multicast bus; none talk USB.
Browser	UberSDR tab + OmniSDR tab	The operator's two tabs talk to each other via postMessage (the bridge inside the UberSDR page).

Want to try it?

Open omnisdr.on8st.be. Don't open UberSDR yourself — when you click a signal on the OmniSDR spectrum, OmniSDR opens the UberSDR tab for you and tunes it in place. (A separately-opened UberSDR tab won't be picked up: the postMessage bridge only works on the tab OmniSDR launched, since it's the one that holds the window.opener handle.) On the LAN, the Targets menu also exposes any rigctld instance found on the network.

Source code

The OmniSDR source lives at on8st/omnisdr on GitHub. The repo is currently private, but I'm happy to flip it public if there's interest — drop me a note (stan@on8st.be / ON8ST) and I'll open it up.