[MLB-WIRELESS] External aerial, what cabling?

[David Ashburner]

On Apr 3, 2006, at 8:19 AM, Zoe Marshall wrote:

> I am in the process of gathering components to mount an aerial on the 
> roof .
> I'm relatively new to wireless networking, but i've done my homework
> regarding coaxial cabling and found that the cabling I should be using 
> is
> CDF-400 / LMR-400 or uncommonly, RG-213.
>
> I need to run a 7-9 metre run of this cable, however which cable I am 
> unsure
> of. I have found premade cables this size to be rather expensive. Are 
> there
> any cheaper alternatives to the coax types I listed above which will 
> do the
> job just as well with low loss, or perhaps somebody could direct me to 
> where
> I may be able to acquire a cheaper premade cable?
>
> Thanks,
>
> Zoe
>
>
Zoe,

I think you will find that any cable of lower spec than LMR 400 is 
going to have too much loss to be of any use.
The going rate for 400 is something like $4-5.00 per metre plus $10 per 
connector.

If you need 9 metres of cable then perhaps you should think about 
locating your radio closer to the antenna.
You will loose something like 1.8 db of signal with lmr 400 ( about 1/3 
of your power ) and 3.3 db with RG 213 ( over half your power )

What sort of set up are you thinking of?  Most recent nodes tend to be 
based around a linux router/AP mounted in the roof or on the pole,
something that allows you to have much shorter coax runs.

cheers,
dna