Transmit

Support

Transmit support for:
  • LSB, USB, AM, Narrow-FM
  • Full-Duplex using RX1/2 and TX1/2 with the Lime USB (the Lime Mini only supports RX1 and TX1).

Options

Select transmit options from either:
  • Ribbon bar, Transmit, DSP.
  • The [•••] button in the top pane of the DSP options.

Power Supply

Use an external power supply (PSU) with the Lime USB when transmitting. The recommended voltage is 8v, more than this is just dissipated as heat.

Sample Rates

RX and TX sample rates are closely tied in the Lime's LMS7 chip. The RX/TX ratio can only be a power of 2 and is also limited by other factors.

Lime Mini: Transmit is only supported for 750 kHz.

Calibration

To calibrate the transmitter select TX Calib (see options below)., this will reduce the spur in the centre of the transmission. Currently the transmitter is not automatically calibrated by default. Some users are reporting improved calibration (spur reduction) when the unit is properly cooled.


⚠️ The transmitter should be recalibrated when you change band and / or power level (drive).

Drive Level

When the Lime runs at full output power the Intermodulation Distortion (IMD) gets worse, so you must not apply too much drive. The Drive control in the console can be customised, more information is here [link].

More...

Full transmit support information is here [link].
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