although many materials may be used for the dielectric 24 e g hard plastic such as peek table 3 below illustrates the output of the model using dense teflon u2122 as the dielectric 24 some of the benefits of using a material such as peek or teflon u2122 as the dielectric include that these materials may be produced by injection molding or conventional machining and grinding of a solid piece in addition precise dimensions may be obtained thus a transition 20 made with a peek or teflon u2122 dielectric is easy and inexpensive to produce the flat surface 28 of the cable trough line 22 shown in fig5 8 provides a bonding surface which may also be produced inexpensively and in large numbers despite its small size therefore the preferable material for the dielectric 24 and 27 for the transition 20 is a material such as peek or teflon u2122 the degree of precision necessary for the dimensions of the transition 20 must be determined for the particular material used for the dielectric 24 and 27 with consideration of the methods used for constructing the cable trough line 22 fig9 and 10 show a fixture 40 that may be used to determine the sensitivity of a coaxial line 39 s impedance to the dimensions of the cable trough line 22 k connectors u2122 which are well known in the art may be used to interface the fixture 40.