QO-100 Transponder Monitor

Transponder status

transponder

–

beacons tell

signals now

–

SSB / CW / digital

–

active signals by segment

passband in use

–

kHz of the 500 kHz

stations decoded

–

FT8 / FT4 / CW, last 15 min

transmissions 24 h

–

over the beacon

–

LEILA territory

Live waterfall · 10489.500–10490.000 MHz downlink

waiting for the receiver…

Who is whereevery signal above the noise · newest first · ● = on air now

Downlink	Uplink	Segment	Width	Peak	Started	Length

Uplink for a downlink frequency:MHz downlink →2400.150 MHz uplink(offset 8089.500 MHz, transponder is non-inverting)

Occupancy now

Stations decodedFT8 · FT4 · CW, last 15 min, live

Station	Locator	Country	Mode	SNR	Downlink	Last	Message

stations 24 h

–

busiest hour

–

decodes today

–

Beacons

The PSK beacon at 10489.750 MHz is the reference: its measured offset is the receiver's LNB drift, every decoded channel is corrected with it. Values are SNR per 250 Hz bin at this receiver, not absolute levels.

Where the decoded stations arelocators of the last 24 h · brighter = heard in the last 15 min

Occupancy · 24 hhow full each band-plan segment was, minute by minute (UTC)

Transmissions · 24 hper hour (UTC)

Stations decoded · 24 hper hour (UTC) · line: SSB signals

Beacon SNR · 24 hrain fade and receiver health

Stations decoded · 7 daysdistinct stations per day (UTC)

PSK beacon bulletin

no telemetry frames decoded yet

AMSAT-DL's 400 bps BPSK beacon carries telemetry and news in 64-character text lines; decoded with gr-satellites.

Band planAMSAT-DL · downlink / uplink MHz

Downlink	Uplink	Use

Max 2.7 kHz bandwidth, no FM. Never louder than the beacons. Keep the guard bands and the emergency frequency clear. Downlink is vertical linear, uplink RHCP.

About this monitor

How it works. A dish with an LNB feeds one RTL-SDR on a small server. A Python receiver (open source, qo100-station) reads the whole 500 kHz narrowband transponder, measures the three beacons, finds every signal above the noise floor and tracks it as a transmission, decodes the FT8 and FT4 channels with WSJT-X's jt9, runs a CW skimmer on the CW segment and gr-satellites on the PSK beacon, and publishes everything over MQTT. This page listens live; a recorder keeps 30 days of history. Callsigns, locators and reports are what the stations transmit openly on the transponder. Operated by DL1TJ in Regensburg, Germany (dl1tj.de ↗, LEO satellites: SatNOGS station ↗); not affiliated with AMSAT-DL or Es'hailSat.