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Re: Update 6th March Version 2

Posted: Wed Mar 11, 2020 11:17 am
by OH7FES
VK3KYY wrote:
Wed Mar 11, 2020 10:43 am
BTW.

There is a calibration setting which controls the output gain from the audio DAC

Do you need to have your volume control very high to hear the audio. If so it may be a calibration problem which is causing this
GD 77 receiver is ok. but transmission TX transmits little noise that is audible in example parrot or other DMR radio.
Ari

Re: Update 6th March Version 2

Posted: Wed Mar 11, 2020 11:34 am
by OH7FES
volume control level has no effect at all to this.

GD77 parrot test

Display options: Brightness:100%
Sound options:DMR mic:12db

mp3 audio file
https://qsl.net/oh7fes/parrot_test.mp3

Re: Update 6th March Version 2

Posted: Wed Mar 11, 2020 8:58 pm
by VK3KYY
OH7FES wrote:
Wed Mar 11, 2020 11:34 am
volume control level has no effect at all to this.

GD77 parrot test

Display options: Brightness:100%
Sound options:DMR mic:12db

mp3 audio file
https://qsl.net/oh7fes/parrot_test.mp3
There is an audio output control setting in the calibration data, which can only be adjusted via the CPS, calibration screen

Re: Update 6th March Version 2

Posted: Wed Mar 11, 2020 9:22 pm
by G4EML
DMR Mic set to 12dB is very high gain. In fact it is the maximum gain. Probably not surprising it is picking up noise.
Normal setting is 0dB.

Re: Update 6th March Version 2

Posted: Wed Mar 11, 2020 9:38 pm
by VK3KYY
G4EML wrote:
Wed Mar 11, 2020 9:22 pm
DMR Mic set to 12dB is very high gain. In fact it is the maximum gain. Probably not surprising it is picking up noise.
Normal setting is 0dB.
Colin

Thanks.

I'd not spotted that..

if OH7FES has to set his DMR mic gain that high, he has probably got a faulty mic in the radio, or simply needs to speak louder. Or perhaps he's using an external mic, which are often badly designed.

I had to modify my external mic by drilling a large hole in front of the mic insert. The original hole was only around 1mm in diameter.

Re: Update 6th March Version 2

Posted: Thu Mar 12, 2020 1:28 am
by OH7FES
G4EML wrote:
Wed Mar 11, 2020 9:22 pm
DMR Mic set to 12dB is very high gain. In fact it is the maximum gain. Probably not surprising it is picking up noise.
Normal setting is 0dB.
GM
i am not using an external mic.
ok now parrot testing mic: 0db
both speak audio voice is normal and ok (display light off and on)

Display options: Brightness: 100%
Sound options: DMR mic: 0db
you hear background noise when the screen background light is ON
https://www.qsl.net/oh7fes/parrot_display_on_0db.mp3

Display options: Mode: None
Sound options: DMR mic: 0db
No background noise when the screen background light is OFF
carrier is clean
https://www.qsl.net/oh7fes/parrot_display_off_0db.mp3

My own notices: Screen brightness is the main thing. If it is 100%, digital noise is heard. Noise disappears when I set it to less than 10%.

Noise goes up as the brightness % goes up.

There is no background noise when Mode: None in Display options (no light on the display).

The noise is detectable in the VU meter bar in the top left of the display when I press PTT = TX. The greater the disdplay brightness, the greater the background noise and the higher the VU bar. Of course the VU meter background noise disappears when display options Mode:None.


OH7FES Ari