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Re: "I sent a photo of my cat 630 miles over the air"
Interesting. Too bad the link refers you to facebook, and telegram (which I am not sure about)
Lora with 10km range on ESP32s winth no license is also interesting
โ โ https://en.m.wikipedia.org/wiki/LoRa
May 14 ยท 4 months ago
๐ Addison [OP/mod] ยท May 15 at 02:56:
@decant Yes! The bottom portion of most HF bands is reserved for non-voice modes (packet radio, RTTY, FT8, etc). Many digital modes transmit on the upper sideband in those portionsl
๐ Addison [OP/mod] ยท May 15 at 02:58:
@stack On top of that, the software required is closed-source. Today I've been checking out freedv/FreeDATA, which is a GPL-licensed packet radio modem. It's usable but still very new, and there aren't many hams using it.
โ https://github.com/DJ2LS/FreeDATA
LoRa is indeed very cool.
๐ก Queen_City_Nerd [mod] ยท May 15 at 23:48:
Wow that's fun stuff. Back many moons ago I used to tinker with SSTV and Slow Scan TV on ham radio was a blast. You still find some folks doing it on 40m and 20m. The ISS sometimes sends a SSTV image and also a digital SSTV of the same thing. The digital is so fast you can really appreciate the difference. I think people forget all broadcast TV is radio and the before the digital TV it was 2 frequencies one for the audio and one for the picture. GPS is just radio.. insert meme "it's all radio?", "always has been..." ;-) keep at it @addison looking to seeing more positive reports. 73 de N2QFD
๐ Addison [OP/mod] ยท May 16 at 19:39:
@Queen_City_Nerd Thanks for the encouragement! SSTV looks like a lot of fun. I'll be sure to write something here about it when I give it a shot. It's been eye-opening to learn just how little our foundational technology has changed from the start of the last century. 73
๐ stack ยท May 16 at 20:29:
Wheels are still round, in spite of what AI may suggest.
๐ก Queen_City_Nerd [mod] ยท May 16 at 22:26:
here's something else for you to play with if you haven't seen it yet @addison.
https://swradiogram.net/ This is a group that sends a regular broadcast over just shorwave radio to decode with MFSK (FLDigi is a good program) Yeah, digital is the biggest thing to change I can think of for me. Even in our rigs, my TenTec is software defined, there's a little arduino clone in there doing the work. And since getting my ticket in 1993 it's been the sort of thing you can come and go from which makes it nice too. best 73!
I sent a photo of my cat 630 miles over the air โ We used VarAC to transfer an 8kb image over the 20-meter band from Portland, OR to Salt Lake City, UT. My antenna is an inverted-vee dipole resonant at 14.1 MHz. It shares a feed point with a 10-meter inverted vee. The transfer took just under an hour. Given my antenna's thin, low-quality wire elements and the thunderstorm over the receiving station, I'm impressed that we were able to complete the transfer at all. I was transmitting at 45 Watts,...
๐ฌ Addison [mod] ยท 8 comments ยท 4 likes ยท May 14 ยท 4 months ago