🚀 go-pugleaf

On 20 Jul 2006 12:21:39 -0700, "Vitaliy" <vmykhayl@ee.ryerson.ca> wrote:

>Hello,
>Can someone please explain me how the coaxial cables work?
>I'm looking for low loss BNC and SMA cables - 50 Ohm. Low loss is a
>requirement, and as long as the  price is not $1/ft for 500ft, any
>reasonable price is ok. Most of my applications are <200MHz.

How much loss can you tolerate? What are the frequencies your application
will be using? What is your RF budget? What distances will you be transmitting
your signal(s)? What will you be transmitting, RF or data? Do you need to run
the coax around tight corners? Do you need coax that is low smoking and free 
of halides? 

All coaxial cables (and connectors) exhibit attenuation (loss) over distance.
Do you consider $1/ft too expensive or too cheap?

>I see here http://www.gme.net.au/land/antennas/coax_cables.php
>that RG58AU is a low loss BNC

RG58AU is a type of coaxial cable. BNC is a type of connector. Distributors
that describe a BNC coax cable are talking about a cable that is terminated
with one or more BNC connectors.

Many BNC connector manufacturers have versions of their connectors 
for crimping, soldering, or just screwing them onto the prepared RG58 cable.

>from the data here http://www.ssbusa.com/comaircom.html
>RG 213 seems to have even lower loss value

Yes, but it has a larger diameter than RG58 and is more rigid. I recommend
using crimp connectors to terminate RG213 coax because soldering the terminal
pin is a bugger without melting the dielectric slightly. And it takes practice.

>Now, on that last website ECOFLEX has even lower db loss. Ecoflex 10
>can work with BNC, does it mean I can use it as conventional BNC cable,
>just with low loss?

Yes if connectors are available, and its probably a good deal more expensive too. 
And 10mm diameter as opposed to about 6.5mm to 7mm for RG58 (I think) 
But with the extra copper shield the ECOFLEX 10 will be somewhat more rigid 
than the RG58. 

>I read the BNC connectors are for average speed and SMA connectors are
>for high-speed. Is it true? And can I place BNC, SMA and SMB connectors
>on the cable from the same spool?

What is "average speed" and "high speed"? The simple answer is to ask the 
cable manufacturer/distributor which connector is suitable for the cable for 
your application. They should have a list of preferred  connector manufacturers 
and any suitable connectors.

>Thanks,
>Vitaliy