• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

Pro 106 with no audio - bad DAC?

Status
Not open for further replies.

johnmbb

Member
Joined
Nov 27, 2012
Messages
8
I got a Pro 106 that had a bad DSP chip and wouldn't startup past the "DSP Loader" message. After replacing the DSP it seems to be working except that there is no audio. There is a good audio signal at the demodulator IC and all the signal strength bars show on the display when I tune to a local radio station and the squelch is open with the squelch indicator on the display. The audio amplifier is good too. Could there be a problem with the TLV320aic13c ADC/DAC IC? I don't have a service manual, and I can't find any traces coming out of the digital-to-analog pins, so I am not sure where the audio is supposed to come back from the logic board. Does anyone have a service manual for this who could help me out?
 

johnmbb

Member
Joined
Nov 27, 2012
Messages
8
Update: I started to receive audio after finding that my pll or vco chip was not giving a frequency lock detect pulse to the cpu and the squelch was not opening until I manually gave the cpu the squelch open voltage. It is strange that it needs both of those things to happen before any audio is heard. It looks like I will need a new squelch potentiometer and 1.5 volt regulator for the dsp core. Those parts may not be available, but I will see if there are any alternatives.
 
Status
Not open for further replies.
Top