Re: #audio #audio

 

Hi David,

I will look into this. The last run of DRAWS did not have any value changes in the audio section. You may have found another assembly error.

Thanks,
Bryan K7UDR

On Dec 14, 2019, at 6:13 PM, Basil Gunn <basil@...> wrote:


"I use the 9600 bps connection even with 1200 baud data which just selects the
Kenwood discriminator output (PR9 Output 9600 (bps)) ie. pin 4 on the
mDin6 connector is selected by ALSA setting IN1."

Thank you, this works well with my old board. For the setalsa-tmv71a
script, is the switch file placed in /etc/ax25 manually or does some
other script do that?

To run 1200 baud packet using the discrimintor on the TM-V71a edit
setalsa-tmv71a.sh
MODE_9600_ENABLE=true
and run the script.

I am still having issues though. With the new board, alsa parameters
from setalsa-tmv71a run with the discriminator, I barely get any
modulation at all, judging from the spectrum of measure_deviate.sh -f
1042 -c left .

I looked for a spot on the board to measure V p-p and I noticed that
the 100 Ohm resistors from the low pass audio filters, the ones where
C17 and C20 are removed, are labeled differently between boards. On my
old board, they are marked 101, which I am guessing is 10*10^1
Ohms. On my new board, they are marked 104, which I am guessing is
10*10^4 Ohms.

Audio In is still a bit low on this new board as well.

Could you folks confirm whether or not the "104" resistor could
account for my output sound level discrepancies between my boards?
Should I try to jump those "104" resistors?

Bryan should get back to you on that.

I've attached a photo of the area where C17 and C20 are removed. The
two "104" resistors are the ones in between where those C's were.

David


Join udrc@nw-digital-radio.groups.io to automatically receive all group messages.