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Mobile repeater

Posted: Sat Oct 06, 2007 8:48 pm
by firefighter13669
Can someone explain to me how a Mobile repeater system works I have tried to research this but found nothing.Can I use a mobile repeater in duplux mode.How do they work in the field for quick short transmissions.Any help on this issue would be great!!!

Re: Mobile repeater

Posted: Sun Oct 07, 2007 8:13 am
by spareparts
firefighter13669 wrote:Can someone explain to me how a Mobile repeater system works I have tried to research this but found nothing. Can I use a mobile repeater in duplex mode. How do they work in the field for quick short transmissions.Any help on this issue would be great!!!
http://en.wikipedia.org/wiki/Repeater

Start with the link above. A mobile repeater receives the dispatch frequency and re-transmits it on a separate frequency to a handheld radio. They can be in the same band, or in some cases cross band (VHF/UHF, Lo Band to VHF, etc.

Most have a mechanism where if several units arrive on scene with mobile repeaters, the first unit on scene will assume the local repeater function, with the second and later units disabled.

Manufacturers Links:

Pyramid: http://www.pyramidcomm.com/svr200.html

Vertex: http://www.vertexstandard.com/?cmd=Divi ... isionID=64 , search for VXR-1000

Re: Mobile repeater

Posted: Sun Oct 07, 2007 1:49 pm
by psapengineer
Hi,

In general, mobile repeaters, are not used in the full duplex mode. Often the hand helds are in one band (maybe UHF) and the mobiles are on another band (maybe VHF). If the mobile and hand held are required to be in the same band (called "In Band") another piece of equipment is often required to combine the two simultaneously operating radios into one space (called a duplexer or combiner). "In Band" is often desired so that the portables can be used with out without the mobile repeater in play.

In all cases, the hand held is always half duplex or simplex. It is never full duplex, it can only be talking or listening; not both at the same time.

Implementation of a mobile repeater system has its challenges, drawbacks, and gottchas.

Regards, Bob