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repeater question
Posted: Sat Feb 17, 2007 3:32 pm
by jmr3865
I am looking to add a repeater for my first aid squad. We can either put it on top of a 6 story building that we will actually be using the repeater in, our at our squad bldg which is about 45' tall. The feedline will be about the same. Both are in our center operating area's. Which should we choose?
Posted: Sat Feb 17, 2007 5:14 pm
by Bruce1807
staight off the 6 story but really it depends on the enviroment.
UHF/VHF/800/LB
terrain?
etc. etc.
An easy way is to just try it and see.
the proper way is using software to model it.
Posted: Sat Feb 17, 2007 6:55 pm
by jmr3865
VHF
It can be hilly w/ trees and other buildings in the way. The issue is that we may be inside a building 10-15 miles away.
Repeaters
Posted: Sat Feb 17, 2007 7:43 pm
by bernie
My two bits worth:
I would not expect this repeater to operate inside a building miles from the repeater in hilly terrain.
consider the antenna as a light. Can you see it from a distance, or would it be behind a hill?
The real issue is what is between you and the repeater antenna.
If you can not directly see the antenna, your signal is getting there by bouncing off of objects, as would light.
Under these conditions your coverage will vary due to moisture content of the vegetation. (Terrain Attenuation)
I think you should consider using in vehicle repeaters with UHF/800 hand held radios.
Cross band rather than in band for better repeater performance, as well as the better building penetration of UHF, or 800.
A portable repeater may be useful at disaster sites.
Posted: Wed Feb 21, 2007 10:53 am
by mike m
Actually your FCC license should specify the exact geographical location where you can place the repeater so you should stick to what you are licensed for.
It almost sounds like you are just putting up a repeater at any random location which will lead you or your dept. to legal issues that you probably don't need.
Been there and done that before with installations that didn't meet the correct licensed antenna height but did meet the correct geographical coordinates and vice versa and I wouldn't want to deal with the FCC again on incorrectly installed public safety installations.
M
Posted: Wed Feb 21, 2007 11:24 am
by jmr3865
We are not licensed yet. We don't even have the freq's or the repeater. We are going for a grant for 2 new freq's, the repeater, antenna and license. I am just debating where to put it.
Posted: Wed Feb 21, 2007 12:35 pm
by mike m
you may not have a choice on the actual location as that will depend on the local freq co-ordinator along with the height of the antenna and the gain of the antenna which depends on how far away any potential co channel users are.
Don't purchase anything until you get this information from your license and or the freq co-ordination person.
mike