dsc

AIS, Navtex, DSC
alexandruy2k
Posts: 2
Joined: Sat Sep 30, 2023 3:38 pm

Re: dsc

Post by alexandruy2k »

Hi,

I have a class M personal locator beacon and I want to have a look at what data exactly it's sending out.

With it I've managed to decode the AIS messages so I believe that my NESDR SMArt v5 is working ok. I've also been able to listen to VHF channels using the NFM Demodulator so that's my second proof the my hardware is working relatively well, so I suspect my issue with decoding DSC messages is something to do with an incorrect setting I have somewhere.

I have the DSC demodulator in the screenshot tuned to +400Hz and the RTL SDR tuned to 156.525 MHz. I know technically it's not correct, but I've tried various frequency shifts as it looks like my tuner has a small offset.

Any guidance as tp what sort of things I should try out or look at would be greatly appreciated
DSC call.PNG
DSC call.PNG (340.36 KiB) Viewed 668 times
Thank you very much
srcejon
Posts: 297
Joined: Thu Jan 19, 2023 2:30 pm
Location: London
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Re: dsc

Post by srcejon »

VHF DSC doesn't currently work, as it uses a different modulation to HF.
g0hdi
Posts: 12
Joined: Sat Sep 23, 2023 8:26 pm

Re: dsc

Post by g0hdi »

Ah! That explains why I didn't receive anything on vhf. Nice to know the answer. Thanks for that 73 Brian
alexandruy2k
Posts: 2
Joined: Sat Sep 30, 2023 3:38 pm

Re: dsc

Post by alexandruy2k »

Looks like I wasn't subscribed to the thread so didn't realise that you replied the next day.

Are there any plans to implement DSC decoding for VHF?

If not any recommendations for alternative software in the meantime? I've read about a few but from what I've been able to tell a lot of the other software involves capturing the data with one bit of software and then piping it into different software for actual decoding.
I'm a fan of the integrated AIS decoding that SDRangel has implemented and would be hoping something similar for DSC over VHF
srcejon
Posts: 297
Joined: Thu Jan 19, 2023 2:30 pm
Location: London
Contact:

Re: dsc

Post by srcejon »

I didn't try to get it working, but haven't been successful so far. Will come back to it, but have a few other things to look at first.
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