Will, I think that almost any antenna will give you the 1/2 mile coverage you need, but you might still have problems inside the building, considering the metal roof's shielding.
I assume you're installing the rptr inside the building, so two ideas come to mind. 1. Use a Wilkinson-type power divider and place a unity gain antenna inside the building and another one on the tower outside. You can mount the antenna on the side of the tower and place it a non-resonant distance from the tower. 2. Use "leaky" coax cable to go from the repeater to the place where the tower antenna's feed line goes through the building to the tower antenna; then use regular coax (such as 9913) from there to the tower antenna. "Leaky" coax cable is made with resonant slots in the outer conductor. It's used in tunnels, mines, tall buildings, etc. As I recall a hotel in Reno, NV, had a coverage problem with its UHF rptr feeding an antenna on a roof mounted tower. They installed "leaky" coax in their elevator shaft and that solved the problem. They got great coverage inside the building and for several miles around Reno. Hope this helps. Regards, Dick ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[email protected]> Sent: 04 May, 2006 06:13 Subject: [Repeater-Builder] Building Repeater >I need some assistance from the brains... > > I am installing a small UHF repeater (GR500) at a building complex. The > users are on simplex now, using Motorola HT1250 portables and are having > problems > with "dead spots". The complex covers about 50,000 square feet, mixed > between brick with metal studs, cinder block and some outside covered > areas. The > roof is metal. Communications should not be required more than one half > mile > from the facility. A fifty foot tower is available on the building. Any > suggestions or recommendations for the antenna and mounting arrangements? > > Thanks > > Will 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/
