Transmitting on VHF DMR Repeater not possible

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DL7DW
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Joined: Sat Nov 16, 2019 10:39 am

Transmitting on VHF DMR Repeater not possible

Post by DL7DW » Sat Nov 23, 2019 7:54 am

There seems to be an issue with synchronization on VHF repeaters in the latest from today (23.Nov.2019).

I run my own repeater and can't activate it. UHF-DMR and VHF-Analog is working fine.

When pushing the PTT on GD77 the red LED blinks. It seems like the GD77 is trying to wake up the repeater with no response.
Just one time the repeater could be activated but I can't reproduce that.
Is there a distortion in the data stream of the signal?


What did I check?
-checking parameters of channels = OK (never changed when loading openGD77 firmware)
-checking power on VHF = OK (all VHF analog repeaters work fine)
-checking UHF repeaters = OK
-switched radio off and on = no change
-reloaded codeplug = no change
-disabled the "allow talk around" in codeplug = no change
-checked the latest stable version (22.Nov.2019) = no change
-checking if another VHF DMR Radio can hear the GD77 on the receive frequency of the repeater = NO, it can't
My repeater is on 145,575 -0,6MHz so I transmitted on 144.975MHz. No reception.

After I transmitted with the GD77 on a native Tier1 channel (144.500MHz) my Hytera MD785 could hear the GD77 but the transmission was continuously interrupted.

Andreas/DL7DW

VK3KYY
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Location: Melbourne, Australia
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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Sat Nov 23, 2019 8:59 am

Thanks Andreas

If you switch to FM and transmit does it transmit on the correct frequency ?

Also is it receiving on the correct frequency ?

Someone else reported a similar issue on UHF with their local repeater, but I was not able to reproduce the problem using my hotspot.

If you wake your repeater using another radio, does the OpenGD77 receive the signal from the repeater, i.e I'm trying to find out if its a Tx or an Rx problem.

VK3KYY
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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Sat Nov 23, 2019 9:05 am

BTW.

Did this work on one of the older versions. If so do you know which version ?

DL7DW
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Re: Transmitting on VHF DMR Repeater not possible

Post by DL7DW » Sat Nov 23, 2019 1:15 pm

-in FM it transmits on the right frequency, I can open VHF analog repeaters
-it receives on the correct frequency as I can hear myself on the GD77 when I transmit with my MD785 oder SL2600
-I am not sure, but the first Tier2 firmware with Hotspot function worked.

The firmware.sgl in your Daily Builds folder on Github does not work either but the difference is, with that firmware the radio transmits, the time out counter counts down but the repeater does not wake up.

DL7DW
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Joined: Sat Nov 16, 2019 10:39 am

Re: Transmitting on VHF DMR Repeater not possible

Post by DL7DW » Sat Nov 23, 2019 1:16 pm

Forgot to mention, in the original firmware VHF works normal in all modes. So it does not seem to be a problem in the radio hardware.

VK3KYY
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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Sat Nov 23, 2019 7:15 pm

The file called firmware is the very original version that does not work with repeaters

The firmware does wok with VHF repeaters. But thee are specific cases of it not working with some MMDVM based repeaters

At the moment I don’t know why it does not work with some specific MMDVM repeaters and I have no way to replicate this problem

DL7DW
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Re: Transmitting on VHF DMR Repeater not possible

Post by DL7DW » Sun Nov 24, 2019 7:29 am

My Repeater is a Hytera RD625. Anyway, thank you for your efforts. I am sure there will be a solution soon.

DL7DW
Posts: 14
Joined: Sat Nov 16, 2019 10:39 am

Re: Transmitting on VHF DMR Repeater not possible

Post by DL7DW » Sun Nov 24, 2019 8:13 am

Checked the last firmware (24.11.2019).

Watching the signal on FM tells me that the GD77 is definitely sending a signal to the repeater. It sounds and looks (pulsing) exactly like the signal I send from my Hytera with the difference, that the repeater doesn't answer to the GD77.

On the Hytera you'll see a short pulsing signal, actually the wake up stream, and the repeater is activated.
This pulsing signal is continuously send by the GD77 and the radio doesn't give an error like "Repeater not found".

Putting the repeater-channel into the VFO makes no difference.

As long as the GD77 ist set to a repeater-channel or in VFO-repeater mode, the transmit frequency has an error. As soon as I switch back to simplex (Tier1) everything works fine.

I tried now 4 different VHF DMR handhelds and non of them could hear the GD77 on the repeater receive frequency but the GD77 can always hear other radios.

So I presume the wake up data stream has errors.

VK3KYY
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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Sun Nov 24, 2019 8:46 am

I think some calibration setting is not being applied correctly for VHF. (and probably not for UHF either)

You could try turning off the calibration in the Options menu, but it probably won't fix it

G4EML
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Re: Transmitting on VHF DMR Repeater not possible

Post by G4EML » Sun Nov 24, 2019 8:52 am

I agree it’s probably a calibration error.VHF DMR repeaters are working OK for me.

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