Hey Guys, There has been a lot of interest in the PCGM recently so I'm going do a run 25-50 of them if you're interested. Let me know. Mark Guibord Micro-Node International 702-528-4700 From: App_rpt-users [mailto:app_rpt-users-bounces@lists.allstarlink.org] On Behalf Of Jeff Carrier Sent: Sunday, May 07, 2017 6:32 PM To: app_rpt-users@lists.allstarlink.org Subject: Re: [App_rpt-users] App_rpt-users Digest, Vol 99, Issue 9 Joe, Did you lock it to a GPSDO? Jim mentioned this mod to me about a year ago and I never had a chance to give it a try. My previous overlap area was tolerable but I've added a third transmitter so it may be time to try this finally. On Sun, May 7, 2017 at 10:00 AM, <app_rpt-users-request@lists.allstarlink.org> wrote: Send App_rpt-users mailing list submissions to app_rpt-users@lists.allstarlink.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.allstarlink.org/cgi-bin/mailman/listinfo/app_rpt-users or, via email, send a message with subject or body 'help' to app_rpt-users-request@lists.allstarlink.org You can reach the person managing the list at app_rpt-users-owner@lists.allstarlink.org When replying, please edit your Subject line so it is more specific than "Re: Contents of App_rpt-users digest..." This site is dedicated to the memory of Jim Dixon WB6NIL Today's Topics: 1. RTCM Simulcast and 9.6 MHz Phase locking (Joe Moskalski) 2. Re: RTCM Simulcast and 9.6 MHz Phase locking (Joe Leikhim) ---------------------------------------------------------------------- Message: 1 Date: Sun, 7 May 2017 03:13:26 -0400 From: Joe Moskalski <kc2irv@gmail.com> To: app_rpt mailing list <App_rpt-users@ohnosec.org> Subject: [App_rpt-users] RTCM Simulcast and 9.6 MHz Phase locking Message-ID: <CAES28qyXLtJMUoGqAYk5bKU_eE2Nciq_9QQC48rBDSeZigtgHA@mail.gmail.com> Content-Type: text/plain; charset="utf-8" I wanted to throw this email out to the group for all those who want to simulcast with the RTCM. For those who don't know, in order to make the RTCM suitable for simulcast you must have a more accurate 9.6 MHz clock for the RTCM in order to ensure the audio sounds acceptable in the overlap areas. I did this a few months ago using 9.6 MHz OCXO's. This worked reasonably well. Not as well as I would have liked but the system was very usable, but of course I wanted it to be better. Since the PCGM (Programmable Clock Generation Module) is no longer available, I decided to roll my own as some say. I created a PLL circuit that can accept a 10 MHz, 1 MHz or 100 KHz reference input and produce a phase locked 9.6 MHz out for the RTCM. I have been testing this over the past few days and it has made an great improvement in the audio quality in the overlap. The quality of the audio in the overlap areas sounds very, very good, it's very similar to what I expect to hear in commercial simulcast systems. My circuit is heavily based off of an old Motorola MSF5000 HSO PLL circuit that I was able to adapt and modify to my needs. There are other uses for this circuit that make it attractive for simulcasting but I wont get into them here. I am will to share my schematic and bill of materials (digikey) with anyone. Please send me an email and I will be willing to share all of my information on the project. <https://www.avast.com/sig-email?utm_medium=email <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> &utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> &utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>