ADPCM Codec, (audio quailty 12) Volume Change Hits, FW 2.20

[VK3ZFS]

Im finding in the 8khz 4bit, ADPCM Codec mode,(audio quailty 12) im getting volume change hits, on the remote to base end, the SIP and  connect status is ok, Im guessing Volume changes aprox 10-13dB in rapid succession, seems to happen 20% of the time, ping time to hosts under 200mS.
73s
Frank VK3ZFS

[sm2o]

Hi

What kind of radio do you use ? It's important to know if it comes from the codec it self, or if something get the radio to change the volume setting?

73 de mikel

[VK3ZFS]

Hi Mike,
The Radio at the remote end is a Yaesu FT-450, the volume is not changed, also to isolate the radio being the cause, I have unplugged the CAT interface.
Im suspecting the problem is due to excessive delay on the 3G side, Its like the ADPCM codec looses its reference and the next packet it gets It cant remenber the last packet volume, I have updated to Ver 2.25 FW
Im guessing the Codec is at its Limit with my shaped and delay link.
73s
Frank VK3ZFS

[sm2o]

OK

Then we are sure about that the Radio settings is not changed, We will try to simulate it and see what's happen.

73 de mike

[SA6BOL]

Hi

I just tested the ADPCM (audio quality 12) in a lokal IC-706MkIIG setup at a private WLAN net. Just as described in the earlyer post, the listeng volume suddenly "explodes" to a very high level starting at some milliseconds breake in the WLAN connection. The high volume continue for up to 45S, or to the next WLAN short breake - then it goes back to normal again. The firmware used is 2.25.


With best regards /BOL

[SA6BOL]

I have just tested the new 2.26 firmware regarding the volume changes in earlyer version of audio quality 12. The setup have being on-air for some time now without any volume explosions. So the high compression - low speed audiosetting now works perfekt. Good Job!

Best regards /BOL
 

[VK3ZFS]

I have loaded FW 2.26, it now works much much better, as a experement I ran a voice only radio programme accross the link using ADPCM, lt  good as a G711 Telephone Codec, ill give a 4/5 for qualiity, its a solution to my 3G wireless link
Thanks for the Great Work Mike
Regards
Frank VK3ZFS QF22MI