Question about Si5351

[Bleach665]

Anyone tried to use this lib with Si5351? If so, pls share a code to encode/transmitt FT8. Thx in advance.

[aa2mz]

Would be great was the chip already has a clock device. Could directly generate RF.

[kgoba]

There are a couple of FT8 transmit projects that use Arduino + Si5351, just search for them on github. For example, https://github.com/kholia/Easy-FT8-Beacon-v3. In essence, you can use ft8_lib to generate the tones (numbers from 0-7) and then use some timing mechanism to control the Si5351 frequency. It can be done, it works, and there should be no issue with that given that you conform with your local radio regulations, have a well engineered TX/PA/filter stage, and conform with band etiquette (if you're transmitting on the public FT8 frequency, sync your transmissions with GNSS/network time).

[Bleach665]

@kgoba , thanks. Yes, it works. Right now I use JEncode to encode string to FT8 and transmit it via si5351. Work fine, but JEncode has some issues.

use ft8_lib to generate the tones and then use some timing mechanism to control the Si5351 frequency.

Exactly this I try to found. Include timings, tone spacing etc. I think somebody has already done it with ft8_lib and I will not need to tune this parameters again.

[kholia]

@Bleach665 Hi! - Yep - JTEncode has a bunch of encoding issues for FT8 messages.

Please see the following projects for your use case:

• https://github.com/kholia/Easy-Digital-Beacons-v1
• https://github.com/kholia/Easy-Beacons-STEM

All the best.