Re: Troposcatter with RDS. Comparing RDS Spy with SDR Console native RDS decoder


Please - it's ALL Simon, really. He is the guilty party in this endeavor. I'm just an over educated gadfly on the sidelines. And, indeed, SDRC is so fantastic it's hard to believe looking at it from a "first licensed in 1959" vantage point.


On 20220206 01:50:00, h. garcia wrote:
Hey Simon, JDow -- very good morning to you and everyone in the reflector.

I've been reading the exchanges in this thread and I found it fascinating! Thank you so much!

To be honest, I've haven't checked if we have more recent topics on the WFM MPX demodulador and the RDS modem.

Anyways, just wanted to share how impressed I'm with the RDS decoder available in small radios like Sangean DT-800 or XHData D-808 leveraged by Skyworks (former SiLabs) ICs Si47xx. 

Like you described before, if one checks the MPX spectrum, very often the RDS carrier is obliterated by the audio peaks. BER indicator (RDS Spy shows it) improves a lot during soft music ou pauses/silences. 

Nevertheless, the Si47xx seems to cope way better these scenarios. I've got a station where the DT-800 shows the station name in no more than 10-15s. Over the PC, sometimes it takes 2 min to show up.

I've been checking the Si47xx documentation and they includes some very clever DSP techniques to condition the RF signal and MPX output. For instance, the IC is aware of selective fading and tries to handle that. 

Unsure how this helps the group, hi! Just wanted to share Si47xx seems a really nice piece of FM and RDS and its documentation, despite not revealing how it's done, shows all real life constraints the IC designers had to overcome.


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