Transmitting on VHF DMR Repeater not possible

VK3KYY
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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Tue Dec 10, 2019 10:24 pm

Ah

Ruki

Perhaps you can pull a version and then build it and see which version introduces the problem

Or tell me approximately which version seems to work i.e which commit code.

post the github url

G4EML
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Re: Transmitting on VHF DMR Repeater not possible

Post by G4EML » Tue Dec 10, 2019 10:48 pm

Roger,

I have just had a look at the history and it looks like around the 10th November was when the frequency resolution was increased by 1 digit to support 6.25 Khz steps so all frequencies were changed to be 8 digits long.

You may need to check my logic but it looks to me like the trxCalcBandAndFrequencyOffset() routine in fw_trx.c is still using the old 7 digit long values. So that would mean that the frequency sensitive calibrations would not work correctly and would always use the last entry in the relevant calibration tables instead of the correct one.

VHF has a wider range of adjustment across the band so it is probably more critical than UHF.

Colin

Riku
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Re: Transmitting on VHF DMR Repeater not possible

Post by Riku » Tue Dec 10, 2019 10:58 pm

OK. commit 089b402 on Nov 9 https://github.com/rogerclarkmelbourne/ ... 259c7350b2
OK. commit 3705d67 on Nov 10 https://github.com/rogerclarkmelbourne/ ... 06132a2c36
NOT OK. commit df55830 on nov 11 https://github.com/rogerclarkmelbourne/ ... 4000efd792

EDIT: if your mmdvm hotspot has the coil of VHF you can test yourself, ber will be over 1% otherwise it is less than 1% use vhf frequency, i used 144.9625 in simplex mode
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VK3KYY
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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Wed Dec 11, 2019 2:08 am

Thanks

Colin has tracked this down to when the resolution of the frequency was changed from 100Hz to 10Hz

I'll test the fix for this later

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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Wed Dec 11, 2019 5:31 am

Can you guys try this version

I've taken Colin's fix and then simplified Kai's original code

Hopefully my simplification hasn't caused any new problems.....
Attachments
OpenGD77_201912111620_VHF_Calibration.sgl
(477.06 KiB) Downloaded 12 times

Riku
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Re: Transmitting on VHF DMR Repeater not possible

Post by Riku » Wed Dec 11, 2019 7:01 am

it is better, its flactuacting but it might be my side problem. ber is less than 1%. it seems it is ok.
just better @DG3GSP try it too to confirm :)
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m1dyp
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Re: Transmitting on VHF DMR Repeater not possible

Post by m1dyp » Wed Dec 11, 2019 7:34 am

this might be related i am not sure, when in vfo mode on vhf, i go to my echolink node 145.2875 and try a ctcs scan, the radio does not stop on 82.5hz (where mine is), however, manually entering it works.
strange?
73 de Ken :D

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Re: Transmitting on VHF DMR Repeater not possible

Post by m1dyp » Wed Dec 11, 2019 7:43 am

incidentally my dual band dv mega works fine on vhf, although this is simplex
73 de Ken :D

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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Wed Dec 11, 2019 8:49 am

m1dyp wrote:
Wed Dec 11, 2019 7:34 am
this might be related i am not sure, when in vfo mode on vhf, i go to my echolink node 145.2875 and try a ctcs scan, the radio does not stop on 82.5hz (where mine is), however, manually entering it works.
strange?
I noticed this problem with the Tone scan and have discussed it with Colin already, and the adjacent ones sometime get through the filter.

I'm not sure if there is much we can do about this, as I don't know if the RSSI or Noise (FM deviation) output from the AT1846RF chip is affected by the correctness of the frequency, or whether its simply passes or fails.

You could try using the RSSI screen to compare whether there is any difference in adjacent Tone's level of RSSI that is recorded.

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Re: Transmitting on VHF DMR Repeater not possible

Post by VK3KYY » Wed Dec 11, 2019 8:56 am

Riku wrote:
Wed Dec 11, 2019 7:01 am
it is better, its flactuacting but it might be my side problem. ber is less than 1%. it seems it is ok.
just better @DG3GSP try it too to confirm :)
OK

I'll merge that change into the Master branch.

Looking at the calibration code, I can still seem some things that could be improved, and some mistakes, which would prevent cross band DMR working.

Anyway, I'll probably merge this initial fix and then take another look to see if I can make any improvements.

e.g. I think I can probably do linear interpolation between calibration points especially on UHF which may improve things a little

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