Tom and group, There is several things you need for simulcasting. I will help if I can.
1-You need a super high stab oscillator, there is ways now to use one and use GPS signals as the time base. 2-Frequency offsets. 2 cycles per transmitter, working out from the link, a good simulcast engineer can help you here. 3-Phasing. The audio must reach each transmitter at the same time, the longest delay is at the closest transmitter to the link transmitter. 4-Audio levels. Audio levels must be set the same across the link to each of the transmitters as read on a good quality audio meter fed by the demod out from a service monitor. 5-Flat Audio. Audio must track the same from transmitter to transmitter from 300 to 3000 Hz within .2 of a dB. Read with same setup as #4. These are most of the things that will give you a good working system. If you use good equipment and set it up correctly it can work well. Suggestion, don't try and link the sites with telephone company land lines. Paul WB5IDM -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Thomas Oliver Sent: Tuesday, May 03, 2005 9:48 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] voting receivers with simulcast transmitters You will need the three transmitters to have uhso (high stab oscilators) to keep them within a few hz of each other, you will have to delay the audio so all three transmitters transmit the audio at the same time. I do not know what effect the multipath from buildings will have on the recieved signal. I think it is worth a shot. tom n8ies > [Original Message] > From: Daron Wilson <[EMAIL PROTECTED]> > To: <Repeater-Builder@yahoogroups.com> > Date: 5/3/2005 8:47:55 PM > Subject: RE: [Repeater-Builder] voting receivers with simulcast transmitters > > > > I guess I wasn't clear enough. I'm familiar with the simulcast paging, this > is not paging. This is public safety police analog repeaters. The proposal > is to put three in a row down the town, about 3-4 miles apart, voting > receivers at the two south ones linked back to the 'main' site via UHF > control links and a voting controller there. So, they would vote the best > receiver and simulcast the output of all three repeaters. Not paging, I > know how paging works, I have a VHF pager on a simulcast system. What I'm > looking for is somone who has seen an installation like this or has > experience with it. Personally, I think it will multipath like crazy and > the recovered audio will be crappy. But, if it is a good thing as suggested > in the recommendation, there must be operating systems out there to listen > to. > > Thanks, > > [EMAIL PROTECTED] > > Daron > > -----Original Message----- > From: Repeater-Builder@yahoogroups.com > [mailto:[EMAIL PROTECTED] On Behalf Of Paul Finch > Sent: Tuesday, May 03, 2005 7:07 AM > To: Repeater-Builder@yahoogroups.com > Subject: RE: [Repeater-Builder] voting receivers with simulcast transmitters > > Daron, > > I will tell you what I know about analog simulcast systems. There is > basically two manufactures of this equipment, Motorola and > Quintron/Glenayre. If you want it to be a fairly good sounding system stay > away from Motorola equipment. I worked in paging back when there was still > a lot of analog pagers on the air, half our systems were Motorola, the other > half Quintron. We finally gave up on the Motorola systems running analog, > you could set them one day and they may work OK but the next day they would > not. There is a problem how the built their FSK modulators, they were not > matched like Quintron's. The Quintron modulators were matched to .2 of a dB > between them, Motorola did no matching. > > The trick that will help the most with either system is; try and keep the > overlaps where people will not be using the system. > > There is other problems with Motorola's simulcast system but that is what > kept them from having a good (as possible) running simulcast system. > > There is still a company in Quincy Il. that sells the Quintron (now > Glenayre) line, their company name is ISC Technologies. They have the > manufacturing rights for most of the Quintron/Glenayre line or they may have > some used equipment available. > > Paul > > > -----Original Message----- > From: Repeater-Builder@yahoogroups.com > [mailto:[EMAIL PROTECTED] Behalf Of JOHN MACKEY > Sent: Tuesday, May 03, 2005 2:00 AM > To: Repeater-Builder@yahoogroups.com > Subject: Re: [Repeater-Builder] voting receivers with simulcast > transmitters > > > Daron- > > Most all your 150 MHz or 900 MHz paging systems are going to be simulcast. > If there are any 150 MHz analog paging systems around, try listening to > them. > > ------ Original Message ------ > Received: Tue, 03 May 2005 01:26:06 AM CDT > From: "Daron Wilson" <[EMAIL PROTECTED]> > To: <Repeater-Builder@yahoogroups.com> > Subject: [Repeater-Builder] voting receivers with simulcast transmitters > > > Hello Folks, > > > > I'm looking over a radio study done by consultants for our small coastal > > community. The recommendation includes three simulcast repeaters with > > voting receivers. We live on the coast, the terrain is covered with tall > > trees that make wonderful reflectors and contribute tons of multipath when > > wet, and it rains plenty. I can't think of any place with terrain issues > > where I have seen a simulcast VHF repeater system built out. > > > > If you have any references (for or against) a simulcast system like this, > > please drop me a note. I suspect a fair amount of multipath problems and > > not real great audio for the mobile units based on their location, but I > > wouldn't be able to prove it until the thing got installed. > > > > Ideas? > > > > Thanks, > > > > > > > > Yahoo! Groups Links > > > > > Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! 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