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[TA2STO]

Hi,

I have developed a new chirp based text chat application.

Specifications: 7 chars/sec, SNR: -12db , Eb/No = 5 db.

Currently I have tested it with IC7300, FT991a and IC705.

It's performance seems to be much better than other comparable modes like PSK31, RTTY. etc.

I need help for testing with other radio models. Please let me know the radio model you have and I will include it in the radio list for your tests.

You may download the software, brief info and the user manual at the link below:

https://drive.google.com/drive/folders/1G5DnKJXxJhi33GzugZ-eHWpfGYjEVhSI?usp=sharing

LongChat can be tested with only one radio and PC by enabling the "rx while Tx" option in the setup menu.

Thanks in advance for your support  in testing.

[K4FMH]

Hi Oguz,

Thanks for the post. Interesting development as I just quickly looked at the brochure and manual.

There is no disclosure as to whether you plan for this to be a commercial or "free" (free as in beer or free as in thought or both) software. Before eHam viewers get into testing it for you, could you tell us what your plans are for eventual release?

This could answer one of the long-term criticisms of FT8/4 that JS8CALL attempted to improve upon.

73,

Frank
K4FMH

[N6YWU]

Is this yet another opaque chuck of software with some secret-by-obscurity algorithm? 
(The FCC should declare these modes illegal in amateur bands IMHO, if they aren't already.)

Or is the new mode to be an Open Standard with a readable specification that can be (re)implemented in an OS, library, CPU, and programming language independent manner by independent teams?

If the latter, excellent experiment!

[TA2STO]

Hi Oguz,

Thanks for the post. Interesting development as I just quickly looked at the brochure and manual.

There is no disclosure as to whether you plan for this to be a commercial or "free" (free as in beer or free as in thought or both) software. Before eHam viewers get into testing it for you, could you tell us what your plans are for eventual release?

This could answer one of the long-term criticisms of FT8/4 that JS8CALL attempted to improve upon.

73,

Frank
K4FMH

Thanks for the comments Frank.

 Sometime ago I read an article of  PA3FWM ( Pieter-Tjerk de Boer) at https://www.pa3fwm.nl/technotes/tn09b.html  It gave me a valuable insight to compare different digital modes. In the light of this article, I have been working on this software since one year. 

- Would this software be free ? If the community thinks that it is useful then it needs to be maintained, developed and updated through its lifecycle. This itself becomes a full time work. I have an immune system disorder (Myasthenia Gravis) which keeps me home and without energy for most of the time. I think it's fair enough to ask for a donation or a very small one time fee for the continuous development and maintenance of the software.

- My tests at home were limited. The results were encouraging. But as long as it's tested and used by more people it will not be validated for sure.

[K4FMH]

Hi Oguz,

Thanks for the post. Interesting development as I just quickly looked at the brochure and manual.

There is no disclosure as to whether you plan for this to be a commercial or "free" (free as in beer or free as in thought or both) software. Before eHam viewers get into testing it for you, could you tell us what your plans are for eventual release?

This could answer one of the long-term criticisms of FT8/4 that JS8CALL attempted to improve upon.

73,

Frank
K4FMH

Thanks for the comments Frank.

 Sometime ago I read an article of  PA3FWM ( Pieter-Tjerk de Boer) at https://www.pa3fwm.nl/technotes/tn09b.html  It gave me a valuable insight to compare different digital modes. In the light of this article, I have been working on this software since one year. 

- Would this software be free ? If the community thinks that it is useful then it needs to be maintained, developed and updated through its lifecycle. This itself becomes a full time work. I have an immune system disorder (Myasthenia Gravis) which keeps me home and without energy for most of the time. I think it's fair enough to ask for a donation or a very small one time fee for the continuous development and maintenance of the software.

- My tests at home were limited. The results were encouraging. But as long as it's tested and used by more people it will not be validated for sure.

Hi Oguz,

So sorry about your illness. You've answered my questions. Good luck on the work as it's very interesting!

73,

Frank
K4FMH

[TA2STO]

Is this yet another opaque chuck of software with some secret-by-obscurity algorithm? 
(The FCC should declare these modes illegal in amateur bands IMHO, if they aren't already.)

Or is the new mode to be an Open Standard with a readable specification that can be (re)implemented in an OS, library, CPU, and programming language independent manner by independent teams?

If the latter, excellent experiment!

Thanks for the comment.

I partially replied to your question in my reply to Frank.

- There is no secrecy around algorithm. It uses chirp signals and Reed-Solomon error correction codes. I did found out some innovative details while experimenting. For example by measuring chirp signal frequency shift, it's possible to calibrate the radio frequency of one radio if your second radio is well calibrated. Also I found a nice way of accurately measuring SNR which helps to decrease the transmission power to minimum levels.

- If you can have a look at the article in my reply above, it will be obvious that almost all of the digital modes including mine, are well below the performance limit set by the Shannon's channel capacity theorem. So there is a lot of improvement capacity for the  digital modes

-Although I found the performance satisfactory, there are many issues to be solved. Unlike CW or voice communications , ıt's not possible to see the weak signal at the waterfall (unless power is intentionally raised)

- I also did not have a chance to see what happens if more than one chat takes place at the same frequency.

[N6YWU]

There is no disclosure as to whether you plan for this to be a commercial or "free" (free as in beer or free as in thought or both) software. Before eHam viewers get into testing it for you, could you tell us what your plans are for eventual release?

This could answer one of the long-term criticisms of FT8/4 that JS8CALL attempted to improve upon.

JS8 actually has a severe problem in this area.

The FT8 encoding and modulation scheme is well documented in a ARRL published QEX article (July/August 2020 issue).  Several independent implementations exist, in C++ and Python.  I even have an FT8 demodulator running on my iPhone. 

No such language independent specification document exists for JS8.  Just opaque Fortran source code, which I regard as inadequate for any "standard" protocol to be acceptable to the amateur radio community.

[TA2STO]

Video of LongChat waterfall and the chirp sound. A bit annoying, you may the turn the volume down.

https://drive.google.com/file/d/1qo8XU_hN3mKW0VCiCCQzLLZ4o5o1dD8x/view?usp=sharing

[KG5ZMG]

This is really cool and what Amateur Radio is all about! Very excited to see people finding new ways to get on the air! Please keep us posted on your progress.