10base5 (Thick) Terminator ?

Paul Koning pkoning at equallogic.com
Thu Mar 31 16:53:24 CST 2005


>>>>> "Jochen" == Jochen Kunz <jkunz at unixag-kl.fh-kl.de> writes:

 Jochen> On Thu, 31 Mar 2005 14:38:07 -0600 Tom Peters
 Jochen> <tpeters at mixcom.com> wrote:

 >> I'm still looking for specs on thicknet cable-- I know the
 >> characteristic impedance is 50 ohms, but if I knew the velocity
 >> factor and losses at VHF (144 - 148 mhz) and UHF (430 - 450 MHz) I
 >> could use the stuff for my amateur radio hobby. As it is, it's
 >> gathering dust.
 Jochen> AFAIK thick Ethernet cable is more or less RG213. Typical
 Jochen> values are 8 dB / 100 m attenuation at 150 MHz and 15 dB /
 Jochen> 100 m at 450 MHz and a velocity factor of 0.66. 

The Ethernet spec says 0.77, not 0.66 -- foam dielectric, after all.
(0.66 is the usual value for solid polyethylene dielectric.)

It also says max of 8.5 dB attenuation per 500 meters (i.e., 1.3
dB/100m) at 10 MHz; there isn't a VHF spec.  Then again, it's high
grade cable, I'd expect it to do well.

      paul



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