GD-77 Tx retries – updated

posted in: DMR | 5

Just a quick followup post about the incorrect (default) Tx retries setting on the Radioddity GD-77.

Several people have let me know that the Tx Sync Wakeup TOT [ms]  value also needs to be increased to 325


Thanks to Jason VK7ZJA for this original information and also to Rob W1AEX and others who posted screengrabs from Jason’s post to FB.

5 Responses

  1. ken

    great thanks

  2. Roger Clark

    You’re welcome…

  3. EvO

    Many thanks Roger/Jason/Rob!
    But since has been wrote “The DMR specification recommends 2 retries; which means on the GD-77 that the “Tx Wakeup Message Limit” value should be set to 3”, why is Tx Wakeup Message Limit = 4 in the picture?
    Anyway, OK, very well, right now I’m going to write 350ms on my GD77!
    Roger please keep it up!
    Thanks and regards.

  4. Roger Clark

    I set it to 4 as I was doing some other testing of the duplex MMDVM hotspot, where having more retries helps if multiple modes are enabled (not just DMR)

    The “recommended” value is for 2 retries, hence the total number, of tries, would need to be set to 3 to be the “recommended” value (from the DMR spec). However a value of 3 retries (4 tries in total) also works fine.

  5. EvO

    Many thanks Roger, Jason, Colin and Rob!
    In “Modifications, hints, tips and technical information for the Radioddity GD-77dual band DMR digital handheld radio Version 4.1 — 4th April 2019” ( I’ve read the following:

    More reliable DMR repeater operation. Easy
    (Credit to Roger VK3KYY and Colin G4EML)
    If you are right on the edge of coverage of your local repeater and not able to access it with your GD-77 in DMR mode, there is a setting that can help. By default, the GD-77 CPS is only set to try to access the repeater and listen for the ’access granted’ reply from the repeater just the once. You can increase the number of retries to improve your chances of accessing the repeater if your signal is marginal. I recommend setting the following:
    At the left side menu tree, double click on Signalling System.
    On the new window that opens up, set TX Wakeup Message Limit to 3 and TX Sync Wakeup TOT [ms] to 150

    So if there isn’t a typo and the value isn’t outdated, then actually TX Sync Wakeup TOT [ms] is now 150ms.
    Is it so?
    I’m asking for that because I want to improve things on my GD-77 now that I’m using the new firmware gd-77_3.1.8_20190407_RxGroupFix.
    Many thanks Roger and all, please keep it up!

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