Re: DRAWS™ and YAESU FTM-100 for analog and digital modes
Bernard f6bvp / ai7bg
Hi John,toggle quoted messageShow quoted text
I performed audio level adjustment for I found that FTM-100DE VHF
transmitted signal from DRAWS modem was spreading around the TX frequency.
After adjusment this is the result of alsa-show.sh :
===== ALSA Controls for Radio Tansmit =====
LO Driver Gain L:[15.00dB] R:[15.00dB]
PCM L:[-31.00dB] R:[-31.00dB]
DAC Playback PT L:[PTM_P3] R:[PTM_P3]
LO Playback CM [Full Chip CM]
===== ALSA Controls for Radio Receive =====
ADC Level L:[0.00dB] R:[-5.00dB]
IN1 L:[Off] R:[Off]
IN2 L:[10 kOhm] R:[10 kOhm]
CM L:[10 kOhm] R:[10 kOhm]
Here is how I proceeded for level adjustement using alsamixer.
I have set a second yaesu device with a Raspberry Pi, UDRC II modem and
audacity to listen to my packets.
While recording the audio signal, I first changed LO driver gain in
I then stepped down the PCM and then increased it again until the
received signal did not increase any more.
With above levels, the transmitted 1200 bauds FSK signal was clean and
it was copied correctly by adjacent APRS repeater stations.
On average received APRS frames are reported to have an audio level
around 20. AFSK frames are perfectly decoded.
73 de Bernard, f6bvp
p.s. there is a typo in first line of alsa-show.sh dump:
"Radio Tansmit =====" should be Radio Transmit =====
Le 06/04/2019 à 18:22, John Spoonhower a écrit :