[App_rpt-users] Simulcasting with RTCM/voter

[Joe Leikhim]

any more progress on this?


On 3/14/2017 1:54 PM, Joe Leikhim wrote:
>
> "The DAC problem is related to audio phase not launch delay. So the 
> audio will sound bad even with the proper launch delay."
>
> I am just shooting from the hip on this, but would it be possible to 
> insert a preamble into the simulcast stream that the DAC's would each 
> reproduce and some additional circuitry or code could monitor and use 
> to correct the audio phase at each RTCM?
>
> I am sure I am oversimplifying, but, thoughts?
>
> Joe
>
>
> On 3/14/2017 10:33 AM, Tim Sawyer wrote:
>> The delta should be less than 83uS for voice is what I read. Digital 
>> (i.e. P25) needs to be even less, not that that's what your dealing 
>> with here. Of course the signal strength comes into play as well. The 
>> overlap areas are defined as areas where the signal is within 10dB.
>>
>> The Radio Mobile program can accept these figures and plot the 
>> simulcast interference. It takes some doing to figure out but well 
>> worth the effort. I've found it amazingly accurate. I might have an 
>> example plot to share if anyone is interested.
>>
>> The DAC problem is related to audio phase not launch delay. So the 
>> audio will sound bad even with the proper launch delay.
>>
>>
>> On Mon, Mar 13, 2017 at 8:10 PM, Hayden Honeywood 
>> <haydenph91 at gmail.com <mailto:haydenph91 at gmail.com>> wrote:
>>
>>     Thanks for your thoughts Jesse and Tim.
>>
>>     Ah, perhaps that was my issue, I was setting the delay, doing a
>>     99 to save to EEPROM but not rebooting. Perhaps I need to try
>>     this next. Basically the test you have described Jesse is what I
>>     am doing at home.
>>
>>     I believe from what I have read and understand from Joe's
>>     messages, Tim that some error in the launch delay is OK at voice.
>>     I read somewhere over 110uS it starts to become a problem.
>>
>>     I certainly can get away with no PL encoding on the transmitter,
>>     I was merely using it as a means of double checking my audio
>>     phasing. Voice sounds OK, depending on my frequency offset. It
>>     does have a level of distortion however - again maybe due to the
>>     launch delay not being set correctly. I suppose a semi bonus is
>>     that at 6 metres, normal propagation effects cause noise,
>>     crackles, phase cancellations etc so it may just all sound
>>     natural anyway. Sporadic E openings will be interesting though :).
>>
>>     Currently my main site has a significant overlap of my planned
>>     secondary site. I may need to reconsider this to reduce the overlap.
>>
>>     73
>>     Hayden
>>
>>     _______________________________________________
>>     App_rpt-users mailing list
>>     App_rpt-users at lists.allstarlink.org
>>     <mailto:App_rpt-users at lists.allstarlink.org>
>>     http://lists.allstarlink.org/cgi-bin/mailman/listinfo/app_rpt-users
>>     <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
>>     <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
>>
>>
>> _______________________________________________
>> 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 visithttp://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.
>
> -- 
> Joe Leikhim
>
>
> Leikhim and Associates
>
> Communications Consultants
>
> Oviedo, Florida
>
> JLeikhim at Leikhim.com
>
> 407-982-0446
>
> WWW.LEIKHIM.COM
>
>
> _______________________________________________
> 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.

-- 
Joe Leikhim


Leikhim and Associates

Communications Consultants

Oviedo, Florida

JLeikhim at Leikhim.com

407-982-0446

WWW.LEIKHIM.COM

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.keekles.org/pipermail/app_rpt-users/attachments/20170328/baa5be60/attachment.html>