[App_rpt-users] Simulcast buffer value issue

[Hayden Honeywood]

Interesting thoughts Tim... perhaps worth documenting on the wiki?
Even though it was just "in theory", what kind of sync error was it?
Were we talking microseconds or even more?

I have a receiver on a yagi pointed at a distant simulcasted site. I
have noticed on occasion, I can hear the distant simulcasted site
start to send audio underneath the carrier of the site that is closest
(and strongest to me). The distant site is also the master site, and
has the lowest latency, but I'm talking two words worth of audio is
send before my other site starts sending audio. Once they are both
transmitting, I  have not noticed any timing issues (i.e. distortion
etc). I'm not sure if this issue was related to what I posted
previously about the variable audio delay on unkey.

I'm running app_rpt on a Raspberry Pi using a cut down image we use here in VK.

http://vklink.com.au


"When simulcasting the audio from all (non captured) transmitters needs to
arrive at the receiver with in an acceptable time frame (80 us). The DAC
theory was that it didn't start sending audio at correct clock cycle every
time. That would cause the audio to be out of sync between RTCMs causing
simulcast distortion.

As I said, that was the theory. The new theory is that the external clock
source was causing the DAC to trigger inappropriately. I spoke with someone
I met here on the list (Kevin I think its was) who is using a different
external clock and reports perfect simulcast operations"
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