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Re: [TowerTalk] High Power / Low Power ? / better antenna

To: "Randy Molyneaux (ve5 rjm)" <>,<>
Subject: Re: [TowerTalk] High Power / Low Power ? / better antenna
From: "K8RI on TowerTalk" <>
Date: Fri, 5 Jan 2007 22:01:40 -0500
List-post: <>
Reading this I'm assume that you are talking about a repeater installation 
and not an installation for working the repeater. I'm basing that on the 
remark that the area is fairly flat over a 60 mile radius.

IF that is what you are asking then things are a bit more complicated.
what is 145' of minimum loss 1/2" coax
How high will the antenna be?

You also refer to 4 and 8 bay dipoles. How will they be configured? 
Generally when all are mounted on one side of the tower they have a deep 
null off the back. You can basically get a circular pattern by mounting half 
on one side and half on the other side of the tower. If there is an area 
where the null can be tolerated then of course you mount them all on the 
same side.

>I was curiously seeking info on a new repeater and came across many sites, 
>and formulas
> and one in choosing the best overall system for the cost. What would it 
> be.....
> Let's say in choosing equipment everything is fairly close in camparison.
> 50 Watts (100 % duty cycle)
> Let's not disucss options...especially right now?
> 145 feet of 1/2" coax line...(Minimum loss)
> the question is?
> Would you consider an amplifier pushing out 100 Watts at 100 % duty cycle 
> over a 4 bay dipole antenna (8 dbd gain)
> or
> Would you consider 50 watts over a 8 bay dipole antenna (11 dbd gain)

I'd take the 50 watts and the 8 bay dipole for two reasons. It can be split 
with 4 on each side of the tower for a circular pattern. It could have about 
half an S-unit better performance on receive. As most mobiles run around 50 
watts on 2-meters (2-meters is an assumption) now days it'd be a good 

Don't forget a good matching harness takes a fair amount of coax which 
equals some loss.

For a repeater don't forget you are probably going to need 6 cans and those 
will cost more than all of the stuff listed.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2

> overall the area within an 60 mile radius is faily flat.
> All suggestions are welcome
> 73's
> Randy Molyneaux(VE5RJM)
> Michelle Molyneaux (VE5MDM)
> EchoIRLP Node 1710 & 1858
> EchoLink Node 48431


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