Jim, Just a quick question, I am looking into simulcasting, can you please explain what the 9.6MHz is for? is it for the RTCM internal clock or the MSF5000? I thought the RTCM required only a 1PPS the get phase coherence of the modulating signal. I guess that this is the more general question about simulcast: Phase coherence of the modulating signal is required. Is phase coherence of the carrier required for FM simulcast or is locking to a accurate frequency source sufficient? E.g. a rubidium oscillator, which would give you frequency stability but not phase coherence. Thanks Andrew Thanks :-) Andrew Gilbett andrew.gilbett@gmail.com On 31 October 2013 13:03, Jim Duuuude <telesistant@hotmail.com> wrote:
For simulcast ALL OF YOUR TRANSMITTERS NEED TO BE IDENTICAL (ELECTRICALLY).
That means that they need to be the same model of transmitter, and TUNED to be identical as possible.
So, you need to have the same model of MSF5000 at both sites. That's a darned good radio for this purpose.
There needs to be a GPSDO (such as a Trimble Thunderbolt), and an RTCM at each transmitter site. There also needs to be an RTCM and GPS-based timing source physically on the same LAN as the host computer (which also might be one of the radio sites).
Note, if you are intending to use a current model RTCM (or voter board) for simulcast, you will need to modify it for simulcast compatibility (which requires injection of external GPS-locked 9.6 MHz for the CPU), or wait until Mark comes out with the new version of the RTCM that includes the option for this built-in.
Jim WB6NIL
------------------------------ From: petem001@hotmail.com To: app_rpt-users@ohnosec.org Date: Wed, 30 Oct 2013 15:20:15 -0400 Subject: [App_rpt-users] multicasting.
Got a problem with one of my repeater.
I live in Montreal QC, and as many of you know we are bless with a small mountain right in the middle of the city. (Mount-Royal) While if you have the blessing of having a repeater on top of it, the coverage is marvellous. (but I am not blessed at all!!!)
So I have nice repeater to cover the north, east, and south of the city, but the damn mountain prevent me from covering properly the west part of the city.
So I was looking at the rtcm to make a multicast/voter system on the other side of the mountain.
I have a MSF5000 UHF at the main repeater site, would I be able to use that with the rtcm and I can have a TKR-820 as the remote repeater would I be able to use it too? Or I also have a Desktrac that used to be the UHF repeater before the MSF500 came along..
What would I need to do make sure that its all stable? I think I would need at least 2 rtcm, But I would loose the dsp decoding of ctcss and squelch?
Lots of question..
Pierre VE2PF
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