[Antennas] Anyone hear of RT142 coax?

[Bob Nielsen]

On Sat, Mar 09, 2002 at 05:27:35PM -0500, Paul A. Cianciolo wrote:
> Hello Folks,
> 
> Can anyone help me identify some coax.
> It is made by Time microwave systems.  It is called RT142.
> 
> Not RG142 but it looks very similar it is tan doulble shielded and Teflon.
> Cannot located it on the Times site 
> 
> Wonder if it is 50 or 75 Ohms

You should be able to calculate the impedance fairly closely from the
diameters of the inner conducter and dielectric.  Or just compare to
the published dimensions of RG-142.


Z0 = (138/sqrt [e]) log (D/d) 

where

e = dielectric constant, 2.1 for teflon

D = ID of outer conductor

d = OD of inner conductor

Bob Nielsen, N7XY