🚀 go-pugleaf

dmm wrote:
> 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?
Right now we are using RG58, so it's about 16dB for 100m, slashing that
by 8 dB would be good.
The frequencies are anywhere between 5MHz and 500MHz.
I'm looking at somewhere ~$400 for 500ft. Distances - 1 to 3 meters
(maybe 1 or 2 10m ones).
I will be transmitting data and RF.
I don't see the need for tight corners at this point, but it would be
"nice to have" option.
No requirement for low smoking/free of halides, but would be
"nice-to-have".

> 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.
>
Therefore, if, for example, I buy Belden cable, I can just buy BNC, SMB
or SMA connectors for that particular 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.
>
I was also thinking about buying crimp connectors, smothing like this
http://www.integratednetworkcable.com/productDetailsPopUp.asp?idproduct=1071
or from here
http://www.danimex.com/Default.aspx?ID=1363

> >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