Is the LimeSDR refclock output programmable?

I’m trying to get my LimeSDR USB set up for QO100 satellite operation. As the LNB in the sat dish has only a simple XCO built-in it will be necessary to feed an external clock of around 27 MHz into the LNB.

As the LimeSDR has a refclock output, I had the idea to tell the LimeSDR to put 27 MHz on that output. But it seems hardwired to 30.72 MHz. Is there a way out?


Stupid question: can you just generate the needed clock signal on one of the TX ports of the Lime?

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Yeah I guess that’s a pretty smart idea.

Just bear in mind that you can’t have two processes open the SDR at the same time, so I suspect that whatever software you use for the RX will need to set up the transmit stream also.

Nice idea BTW!

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After actually trying, it turned out it doesn’t work because there’s only one TX PLL for both ports, so the actual TX frequency and the generated clock signal can’t be more than some MHz apart. Pity. :frowning: