Transmit
A Transmitter puts a signal on the air through a radio that can send. Nothing transmits until you arm it, and arming is never saved: a workspace always opens with every transmitter off.
You are responsible for what you radiate. Check your licence, the band plan and your antenna before you arm.
Radios that send
| Radio | Duplex | Notes |
|---|---|---|
| HackRF One | Half | Receive pauses for each burst. The 14 dB amp is shared by receive and transmit |
| ADALM-Pluto, AntSDR | Full | TX attenuation per lane on the Device |
| bladeRF, LimeSDR, USRP (Soapy) | Per board | One TX gain per element the board has, set alike on every transmit channel |
| Transceiver, Half-duplex (virtual) | Full, half | Debug builds. What one virtual radio sends, the others hear |
The transmit gain is the TX gain on the Device; a Soapy board shows one per gain element, such
as TX PAD. The radio sends around the Device's centre, so
a transmit frequency has to fall inside the Device's window.
Send a message
- Add a Modulator and pick a mode that sends messages, such as APRS.
- Add a Transmitter. Wire Modulator
basebandto it, and itstransmitto the Device'stransmit. - Set the Transmitter's frequency. Empty means the Device's centre.
- Press Arm.
- Fill in the message on the Modulator and press Send.
The burst goes out once and the Transmitter returns to idle, still armed.
Talk
- Add a Microphone, a Modulator on NFM, AM or SSB, and a Transmitter.
- Wire Microphone
audioto the Modulator, then on to the Transmitter and the Device as above. - Arm, then hold the key on the Microphone while you speak. The keyboard has a key for it too.
The browser asks for the microphone the first time. A channel's audio works in place of the
Microphone: the transmitter then sends whatever that channel hears, keyed by its squelch.
Turn on VOX to key by voice. The Microphone then listens all the time and sends while you are louder than the threshold, and for the hang time after you stop.
Send a channel
Wire a channel's baseband into a Transmitter to send that channel's filtered IQ again, on
another frequency or another radio. Without a frequency it goes out where it is heard, so set one
unless the two radios are far apart.
Send a lane
Wire a Device's iq straight into a Transmitter to send that lane as it is: a recording, a signal
generator, or another radio. Without a frequency it goes out where it was received. A lane as wide
as the sending radio's window has to sit on that radio's centre.
Level, timeout and state
| Setting | Meaning |
|---|---|
| Level | Digital drive below full scale. Leave a few dB of headroom |
| Timeout | The longest one transmission may last. Past it the Transmitter ends the burst and disarms |
The Transmitter shows when it is on the air, its frequency, the peak drive of the last burst and how often the source could not keep up. Width is the band that held 99 % of the last transmission's power. It turns to a warning when a modulator's signal is wider than its mode's channel: lower the level or the audio. An error, such as a frequency outside the Device's window, mutes it until the cause is gone.
Changing a Transmitter's wires while it is armed takes it off the air. Changing its source arms it again on the new one.