HFU HF Underground

General Category => General Radio Discussion => Topic started by: NJQA on December 18, 2019, 1347 UTC

Title: FT8
Post by: NJQA on December 18, 2019, 1347 UTC

A pet peeve of mine is when I hear someone claim FT8 operates with signals below the noise floor.  It works well, but there is no magic here.

https://tapr.org/pdf/DCC2018-KC5RUO-TheReal-FT8-JT65-JT9=SNR.pdf

Title: Re: FT8
Post by: redhat on December 18, 2019, 1800 UTC

That's what happens when critical thinking is no longer common practice  :o

+-RH

Title: Re: FT8
Post by: VK3BVW on December 20, 2019, 2112 UTC

https://tapr.org/pdf/DCC2018-KC5RUO-TheReal-FT8-JT65-JT9=SNR.pdf
[/quote]

Thanks for this! An interesting read.

Rob VK3BVW

Title: Re: FT8
Post by: Josh on December 20, 2019, 2205 UTC

thread hijack!

I've yet to experience a mode where it was decoded and I couldn't still hear it clearly. I've heard from people I trust that they have had certain modes, like pactor iv, become inaudible but still print perfect copy, good psk sounds like noise anyway so a human might not be able to differentiate weak psk from noise but a machine can.

On a like note I think ROS mode, throb, or FM Hell take the first place in weak signal work on hf.

https://rosmodem.wordpress.com/
http://www.w1hkj.com/FldigiHelp-3.21/Modes/THROBdesc.htm
https://www.qsl.net/zl1bpu/HELL/PSK.htm

Title: Re: FT8
Post by: Matt285 on December 21, 2019, 0329 UTC

Personally I have no interest in digital modes, But has a CW op I see the benefits of the mode and Im all for keeping ham radio alive. One of the great aspects of the hobby are all the different options to pursue whether it be HF, VHF, UHF, SSTV, CW, Satellites, FM, digital or RTTY type operation .To each their own. If you enjoy it, then do it!  (Yes im sure I left out modes of operation)