[App_rpt-users] Simulcast buffer value issue

[Sam Skolfield]

Jeff, what are using for GPSDO for transmitters and for 9.6MHz injection
into RTCM clock?

On Tue, Feb 13, 2018 at 8:10 PM Jeff Carrier <k0jsc.jeff at gmail.com> wrote:

> I really hope to be able to confirm this soon.  I've been lazy and our 3
> sites are 86 miles, 79 miles and 70 miles (in a triangle).  One of the 3 is
> over 11,000 feet elevation.  No matter what we've tried so far you still
> hear distortion in the overlap area(s) even when 1 site is 20 miles out LoS
> and the other is around 60 miles out non LoS.  Everything is linked on a
> private uW network with very low latency and basically zero packet loss.
> The transmitters (GE MIII) run about 1hz freq error with the gpsdo attached.
>
> Sometimes I just wonder if this is just multi-path from the various
> granite reflectors we have on the front range of Colorado (one of them is
> Pikes Peak)
>
> de K0JSC
>
> ------------------------------
>>
>> Message: 6
>> Date: Tue, 13 Feb 2018 20:43:42 +1100
>> From: Hayden Honeywood <haydenph91 at gmail.com>
>> To: app_rpt-users at lists.allstarlink.org
>> Subject: [App_rpt-users] Simulcast buffer value issue
>> Message-ID:
>>         <CAC0VLD0-9mc=
>> T8BkvMwx6PqWXqtUXCYY2odbjc2ajjDiVLKSBg at mail.gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> 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"
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL: <
>> http://lists.allstarlink.org/pipermail/app_rpt-users/attachments/20180213/991fdf0c/attachment-0001.html
>> >
>>
>> ------------------------------
>>
>> Subject: Digest Footer
>>
>> _______________________________________________
>> App_rpt-users mailing list
>> App_rpt-users at lists.allstarlink.org
>> http://lists.allstarlink.org/cgi-bin/mailman/listinfo/app_rpt-users
>>
>>
>> ------------------------------
>>
>> End of App_rpt-users Digest, Vol 108, Issue 12
>> **********************************************
>>
>
> _______________________________________________
> App_rpt-users mailing list
> App_rpt-users at lists.allstarlink.org
> http://lists.allstarlink.org/cgi-bin/mailman/listinfo/app_rpt-users
>
> To unsubscribe from this list please visit
> http://lists.allstarlink.org/cgi-bin/mailman/listinfo/app_rpt-users and
> scroll down to the bottom of the page. Enter your email address and press
> the "Unsubscribe or edit options button"
> You do not need a password to unsubscribe, you can do it via email
> confirmation. If you have trouble unsubscribing, please send a message to
> the list detailing the problem.

-- 
KJ6QFS
Sam Skolfield
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.keekles.org/pipermail/app_rpt-users/attachments/20180214/bf39cba7/attachment.html>