How many ham systems use compression?

Discussion in 'Ham Radio Discussions' started by KX4Z, Sep 6, 2019.

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  1. KX4Z

    KX4Z Ham Member QRZ Page

    I only know of eight -- anyone have better information?

    1. WINLINK
    2. FBB
    3. BPQ
    4. PAT
    5. FLMSG
    6. FLWRAP
    7. LINPAC
    8. DRATS
     
  2. WB6CXC

    WB6CXC Ham Member QRZ Page

    WSPR, FT8, etc, use canned compessed formats to map callsign and other standard info into a minimum number of bits. JS8 (JS8Call, based on FT8) also does this, and then uses two different types of compression for the free-format text: Huffman, and dictionary.
     
  3. K0UO

    K0UO Subscriber QRZ Page

    I use some compression on sideband all the time!!!!!!!!
     
    VK6APZ, K4AGO, KF5KWO and 4 others like this.
  4. KX4Z

    KX4Z Ham Member QRZ Page

    Really!?!?! Where did you find that, I had no idea, can you give me a reference somewhere? That is very important information for me
     
  5. WB6CXC

    WB6CXC Ham Member QRZ Page

    Look at the JS8Call documentation: https://docs.google.com/document/d/...C9wd4CuWnetN68O9U/edit#heading=h.3tgucrf80oeu -- the appendix mentions the Huffman coding and the "dense code", which is a dictionary look-up code. The JS8Call sourcecode will show you where and how these are used. This document also shows how callsigns and grids are compressed (this is identical to how it is done in WSPR and FT8.)

    This link also has info on the JS8Call (originally called FT8Call) structure. I think the "dense code" compression was added after it was written: https://github.com/jsherer/ft8call
    The above document also has links to the WSJTX documentation set where you will find detailed descriptions of WSPR, FT8, and the other related modes.
     
  6. SM0XHJ

    SM0XHJ Ham Member QRZ Page

    How do you define compression?
    Compression is commonly used in CW, for example, through the use of Q-code and abbreviations like '73'.
    The PSK-modes can also be said to use compression, they use Varicode encoding that is designed to make the transmissions shorter.
     
    K4AGO and K0UO like this.
  7. KG7FIU

    KG7FIU Ham Member QRZ Page

    Well, although not fully stated, it would appear the author is specifically interested in digital protocols that involve some compression of the bytes in the data stream. He is not necessarily interested in the compression of audio signals.
     
  8. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I use compression on victims with bleeding wounds sometimes.

    Depends on the wound.
     
    KG4RRH, KY5U, K4AGO and 2 others like this.
  9. KX4Z

    KX4Z Ham Member QRZ Page

    THANK YOU!!"!"!! I would never have known thbat. THANKS!!!!

    Are there any others????

    I'm amazed at how many different ham systems are using data compression (not talking about audio compression here, sorry!) -- Gordon
     
  10. KX4Z

    KX4Z Ham Member QRZ Page


    Yes, you are making a very good point. Those things are a form of compression. I’m not sure how to describe the difference, but I was more thinking of things along the line of look up tables that can be variable from one message instance to the next. I think CW & PSK 31 use a fixed look up table, and from what I can tell, so does JS8 , all are indeed compressed, but the compression table is static and unchanging I think
     
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