# Sync both TXs in LimeSDR USB

**URL:** <https://discourse.myriadrf.org/t/sync-both-txs-in-limesdr-usb/13033>\
**Category:** LimeSDR\
**Created:** [3 February 2026 10:13 UTC](https://discourse.myriadrf.org/t/sync-both-txs-in-limesdr-usb/13033 "2026-02-03T10:13:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![andrebarrancos](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@andrebarrancos](https://discourse.myriadrf.org/u/andrebarrancos)\
**Post date:** [3 February 2026 10:13 UTC](https://discourse.myriadrf.org/t/sync-both-txs-in-limesdr-usb/13033/1 "2026-02-03T10:13:45Z")

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Hi,

Im using limeSDR USB with soapySDR and limesuiteNG.

Im trying to change the phase between my two Tx channels.

```auto
fs = 5e6
freq = 80e6
tx_gain = 55
tx_chans = [0, 1]
sdr = SoapySDR.Device()

for ch in tx_chans:

    sdr.setSampleRate(SOAPY_SDR_TX, ch, fs)
    sdr.setFrequency(SOAPY_SDR_TX, ch, freq)
    sdr.setGain(SOAPY_SDR_TX, ch, tx_gain)

tx_stream = sdr.setupStream( SOAPY_SDR_TX, SOAPY_SDR_CF32, tx_chans)

```

Only by doing this, and using the oscilloscope, the phase between the two Txs is not deterministic.

The phase is always changing… It’s -90 or 90 deg.

Do you know how I can sync both Tx channels?

Thanks!

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<div class="post-metadata">

**Author:** ![andrebarrancos](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@andrebarrancos](https://discourse.myriadrf.org/u/andrebarrancos)\
**Post date:** [20 February 2026 16:51 UTC](https://discourse.myriadrf.org/t/sync-both-txs-in-limesdr-usb/13033/2 "2026-02-20T16:51:30Z")

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Hi!

Does anybody know, how can i sync both Tx in limesdr usb?