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mikaelnousiainen / RS41ng

Custom firmware for Vaisala RS41 and Graw DFM-17 radiosondes with support for amateur radio use. Ideal for tracking high-altitude balloons. Supported modes include APRS, Horus 4FSK mode, CATS, morse code (CW) and additional digital modes like WSPR and FT8 via Si5351.
GNU General Public License v2.0
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Will not decode on Kenwood TM-D710 #8

Closed Reid-n0rc closed 1 year ago

Reid-n0rc commented 2 years ago

I can get my FT-2DR to decode packets from the RS41ng, but not my Kenwood TM-D710. It was speculated that there could be a pre-emphasis/de-emphasis issue and could explain why one receiver works, while the other does not.

Has pre/de-emphasis been accounted for?

mikaelnousiainen commented 2 years ago

@Reid-n0rc I have a TM-D710G and it does successfully decode APRS, though it is indeed picky about the decoding. The AFSK encoding is really a hack on the sonde (see README for more details), as it can't really do it properly. There is no filtering/emphasis even possible with the hardware, it has not been designed to output AFSK at all.

mikaelnousiainen commented 2 years ago

@Reid-n0rc There was actually a bug in the APRS call sign field generation for call signs shorter than 6 characters. This could have been the issue indeed if you used a short call sign like N0RC. Can you try to fetch the latest changes from Git and re-flash your sonde to see if it decodes now?

mikaelnousiainen commented 1 year ago

Closing issue with no activity. I've had several reports about successful decodes using TM-D710(G) at least (including mine). However, the APRS modulation is far from perfect, as the hardware cannot properly modulate AFSK, so your mileage may vary.