FT8 on 144MHz.

[lz1zp]

Hello Jason,
Playing with Si5351JTDemo ( using <si5351.h> v. 2.1.4 and <JTEncode.h> v.1.2.1 ) I met the following problem - transmiting of FT8 (also on JT4) text on 144MHz is interrupted on every new tone, breaks and starts of transmition occures everytime frequency has changed. It's looks like Si5351 could not locks the frequencies. This problem is missing on HF, 50 and 70MHz. I've tried with different chips and reference frequencies ( 25MHz, 26MHz and 27Mhz) but without any luck. Any suggestion ?
Thank you very much for your great support to the HAM community !
Best regards,
Georgi LZ1ZP

[lz1zp]

Hello Jason,
The problem is solved. Using " Si5351.set_freq( ) " method needs time to lock the output frequency. As higher as frequency is, it needs more time to lock the desaired frequency on the output - that's why I observed "stop-start" between each tone on FT8 transmition on 144MHz. Using "Si5351,set_freq_manual ()" method to set the frequency corresponding to the "Frequency plan" from ClockBuilder tool is the answer ! It's more code complicated, but it works.....