Remote tuners

Coax loss and noise are worse than network latency, so the right place for a receiver is at the antenna. Point --stream at an IQStream, rtl_tcp, SpyServer or KiwiSDR server, or add it under Add remote…, and it appears in the receiver list as a local radio, dial and all. An IQStream tuner is set from here as well: dial, gain, switches, trim and span.

Public receivers are listed in the same dialog: IQStream stations from their directory on nostr, SpyServers from Airspy’s list and KiwiSDRs from kiwisdr.com, filtered by what they can hear and whether a slot is free. The TUNERS layer on the map draws all three, and CONNECT opens one.

WaveShark serves IQStream too, on port 5555 by default, and answers rtl_tcp and SpyServer clients on the same port, each tuning anywhere inside the span it is collecting. It can list itself in both directories, and it answers a browser over WebSocket, WebTransport or WebRTC, so the public tuners open straight from app.waveshark.io.

Several matching tuners can be offered as one wider receiver: the drift between them is measured on the band they share and taken out, which is how you cover more span than any one radio can.

What it reaches

• An antenna in the loft and a receiver on the desk
• Somebody else’s antenna, picked off a map
• One collected span read by more than one machine, or a browser
• A span wider than any single radio

What it will not do

• Network throughput sets the span you can carry
• rtl_tcp carries 8 bit samples, whatever the radio is
• A KiwiSDR is shortwave only, and a narrow slice of it
• The browser version reaches IQStream servers only

Setup

waveshark --iqstream-listen 5555 on the machine at the antenna, waveshark --stream mast.local:5555 at the desk. Switch on list in the directory settings to put it on the public map.