[App_rpt-users] Simulcast buffer value issue

Thu Feb 15 20:13:12 UTC 2018

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

On Thu, Feb 15, 2018 at 10:50 AM Jeff Carrier <k0jsc.jeff at gmail.com> wrote:

> Here's a down and dirty display of overlap with transmitter power, feed
> line loss, antenna gain, pattern and azimuth figured in.
>
> [image: Inline image 1]
>
>
>> Message: 8
>> Date: Wed, 14 Feb 2018 17:33:50 -0800
>> From: Tim Sawyer <tisawyer at gmail.com>
>> To: Users of Asterisk app_rpt <app_rpt-users at lists.allstarlink.org>
>> Subject: Re: [App_rpt-users] Simulcast buffer value issue
>> Message-ID:
>>         <
>> CAG3ht9t7Unky+Tc0MFTOLg2Z3+pcnoWFM2AyNFKeFcrOeE4cdw at mail.gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>
>
>>
>> 11,000 feet! No way that will simulcast well, not at 70 miles.
>>
>> 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.gm
>> >> ail.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/attach
>> >> ments/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.
>> >
>>
>>
>>
>> --
>> Tim WD6AWP
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>>
> URL: <
>> http://lists.allstarlink.org/pipermail/app_rpt-users/attachments/20180214/3bcc2d18/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 14
>> **********************************************
>>
>
> _______________________________________________
> 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/20180215/f48c21ea/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 912311 bytes
Desc: not available
URL: <http://lists.keekles.org/pipermail/app_rpt-users/attachments/20180215/f48c21ea/attachment.png>