Experimental version to help DMR breakup

VK3KYY
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Location: Melbourne, Australia
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Re: Experimental version to help DMR breakup

Post by VK3KYY » Sat Feb 22, 2020 6:54 am

vk4apf wrote:
Sat Feb 22, 2020 6:19 am
Hi Roger, I put in the 13 frame version and so far no stuttering audio! I was getting stuttering audio quite often.
And the green led doesn't flash on and off either.
This change is now in the "latest" released version, http://opengd77.com/viewtopic.php?f=13& ... 5e3bb69723
which also has 1 or 2 other fixes.

EB2EAS
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Joined: Wed Feb 19, 2020 10:42 pm

Re: Experimental version to help DMR breakup

Post by EB2EAS » Sat Feb 22, 2020 11:43 am

Buenos días Roger.

No sé si será interesante pero he incluido en el menú de opciones el que se pueda modificar este dato. Las pruebas que he realizado son satisfactorias. Así la gente podrá modificar el valor sin cargar un nuevo firm.

Un saludo de EB2EAS José.

IZ2EIB
Posts: 77
Joined: Sat Nov 30, 2019 12:55 pm

Re: Experimental version to help DMR breakup

Post by IZ2EIB » Sat Feb 22, 2020 12:12 pm

VK3KYY wrote:
Sat Feb 22, 2020 6:54 am
This change is now in the "latest" released version, http://opengd77.com/viewtopic.php?f=13& ... 5e3bb69723
which also has 1 or 2 other fixes.
Thanks a lot Roger!

73 best regards de Fabio IZ2EIB

IZ2EIB
Posts: 77
Joined: Sat Nov 30, 2019 12:55 pm

Re: Experimental version to help DMR breakup

Post by IZ2EIB » Sat Feb 22, 2020 12:18 pm

EB2EAS wrote:
Sat Feb 22, 2020 11:43 am
Buenos días Roger.

No sé si será interesante pero he incluido en el menú de opciones el que se pueda modificar este dato. Las pruebas que he realizado son satisfactorias. Así la gente podrá modificar el valor sin cargar un nuevo firm.

Un saludo de EB2EAS José.
Google translator -->
EB2EAS wrote:
Sat Feb 22, 2020 11:43 am
Good morning Roger.

I do not know if it will be interesting but I have included in the options menu the one that can modify this data. The tests I have done are satisfactory. This way people can change the value without loading a new firm.

Greetings from EB2EAS José.

Hi José.
Interesting solution, thank you!

73 best regards de Fabio IZ2EIB

WP3BM
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Location: Puerto Rico

Re: Experimental version to help DMR breakup

Post by WP3BM » Fri Feb 28, 2020 7:30 pm

Greetings,

So far, so good!

73 de WP3BM

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EB3AM
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Re: Experimental version to help DMR breakup

Post by EB3AM » Sat Oct 17, 2020 8:12 am

Hi, up this post momentarily so it's easier to know what I'm talking about.

I've been playing with GD77 for the area I live in, full of mountains. We now have a major network of DMR repeaters, but the orography means that we do not always have them in reach. As you know, the DMR requires a little more signal level than the FM to start decoding audio.

Well, if I remember correctly, a margin of 390ms (13 frames) was left to lose synchronism.

Can an experimental firmware be made with a switch where this time can be increased?

During the February tests it was seen to be enough, but I think a higher time would help in mountain areas.


How about that?
Jordi, EB3AM, Talarn JN02ke, Catalonia.

Radios: OpenGD77 RadioDitty, Icom 7300, mcHF clone QRP,
Repeaters: MMDVM with a Standard RP80-U (DMR + FM), MMDVM + Motorolas (DMR+FM), Hytera UHF DMR+FM repeater.

VK3KYY
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Re: Experimental version to help DMR breakup

Post by VK3KYY » Sun Oct 18, 2020 12:23 am

EB3AM wrote:
Sat Oct 17, 2020 8:12 am
Hi, up this post momentarily so it's easier to know what I'm talking about.

I've been playing with GD77 for the area I live in, full of mountains. We now have a major network of DMR repeaters, but the orography means that we do not always have them in reach. As you know, the DMR requires a little more signal level than the FM to start decoding audio.

Well, if I remember correctly, a margin of 390ms (13 frames) was left to lose synchronism.

Can an experimental firmware be made with a switch where this time can be increased?

During the February tests it was seen to be enough, but I think a higher time would help in mountain areas.


How about that?
This change happened over 6 months ago. But from what I can remember the change was the number frames which needed to enter the audio buffer before the audio decoding, and hence the audio output would start.

This change does not effect the timeslot part of the firmware, so increasing the value will not stop the radio losing synchronisation.

G4EML
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Re: Experimental version to help DMR breakup

Post by G4EML » Sun Oct 18, 2020 10:14 am

The change was to how many lost frames could occur before the signal was considered to have dropped out and the state machine reverted to DMR idle, thus requiring a resync before the signal could return. Increasing the number of allowable lost frames would allow longer fades in the signal. There is a point however where rapid fading will always cause problems.

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