At 05:34 PM 5/3/04 -0500, you wrote: >Ok, so then what about the transmitters, or is it the transmitters that have >to be equal? That is the part that I am missing, because the transmitted >audio into the voter comes in on 146 Mhz, and exits through a transmitter on >902 Mhz. > >Mathew
First, as Plato the philospoher said, "Let's define our terms". You have to be careful how you use the word "voter". To one person it's the unit at the central site that does the actual on-the-fly selection of best received signal at the moment. To another it's one of the outlying receivers. Either way, the voting process is fast enough that the system can select receivers several times each second. The most common usage is that the term "voter" means the central selection unit and the term "voting receiver" means the actual remote receivers that listen to the mobiles and send the audio back to the voter via point-to-point RF links (420, 902, or 1200mhz), microwave links or wirelines. Some work is being done with VOIP but it's very temperamental since the audio has to arrive at the voter at the same instant, and the IP routing is fluid and therefore the timing is not consistent from second to second. Are you saying that your voting receiver sites listen on 146 and transmit on 902, then at the voter site there is a stack of 902 receivers and a 146mhz TX? If so, you need to realize that each voting receiver site listens to the same 2m frequency (the repeater input) and transmits on a unique 902mhz link frequency. At the main site the link receivers feed the voter whose output talks to the regular repeater controller (as if it was the regular 2m receiver). The controller talks to the regular 2m repeater transmitter. In other words it's a regular repeater with a voting selector added to it, and my previous statement stands: >The comment about the receivers that need to be the same >actually extends to the path between the voter chassis and >the user - the RXs and the entire path from the RXs to the >voter. The goal is that the voter sees the users audio from >multiple locations and the only difference between them is >the different RF paths. Using identical equipment at the receiver sites is simply an easy way to insure that the voter sees identical audio characteristics on each voter receiver. The voter does its selection based on audio quality - you HAVE to give it as close to equal audio as you can... The ideal situation is that one user (let's call him user #1) listening to another user (let's call him user #2) cannot tell by listening which receiver user#2 is being heard by, and cannot tell if user#2 fades out from that receiver and the voter switches to another receiver or receivers. My first exposure to voters was when I saw an IMTS system in around 1980-81 that had 6 receivers, and I as I stood there I watched the voter "assemble" a multisyllable word from 4 receivers - and the users never knew that there were multiple receivers involved. A good voter is totally transparent and the users do not know it exists. >There are a couple of voter related articles at >www.repeater-builder.com - use the search function for "voter" Have you read them yet? <http://www.repeater-builder.com/rbtip/remotereceivers.html> <http://www.repeater-builder.com/rbtip/votingcomparators.html> And a manual on a voter intended for the amateur community - read it for the theory and not the sales pitch: <http://www.repeater-builder.com/pdf/rvs.pdf> And a manual on a voter intended for the public safety / military community - again, read it for the theory and not the sales pitch: http://www.jps.com/downloads/PDFS/snv12.pdf Mike WA6ILQ 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! Groups is subject to: http://docs.yahoo.com/info/terms/
