Impendance Hole Sizes

  
            Zo=(138 log d1/d2)/     ------------------	     
	     the sq root of "e"      |       
                                     |     |
	 		            d1    ------------
         d1=hole diameter            |    ------------ 
         d2=pin diameter             |     |
         "e"=dialectric constant     |      --d2
	     in air = 1             ------------------

	|     Zo    |           |   air    |  teflon  |
	| impedance | log d1/d2 | constant | constant |
	-----------------------------------------------
	-----------------------------------------------
	|    5 ohm  |   .0362   |   1.087  |   1.124  |
	|   10 ohm  |   .0725   |   1.182  |   1.268  |
	|   12 ohm  |   .0869   |   1.221  |          |
	|   15 ohm  |   .1085   |   1.282  |   1.422  |
	|   20 ohm  |   .1450   |   1.390  |   1.603  |
	|   30 ohm  |   .2165   |   1.648  |   2.008  |
	|   40 ohm  |   .2800   |   1.950  |   2.570  |
	|   50 ohm  |   .3620   |   2.300  |   3.250  |
	|   60 ohm  |   .4350   |   2.720  |   4.115  |
	|   70 ohm  |   .5060   |   3.215  |   5.210  |
	|   80 ohm  |   .5790   |   3.790  |   6.610  |
	|   90 ohm  |   .6510   |   4.470  |   8.375  |
	|  100 ohm  |   .7250   |   5.304  |  10.600  |

 **example: Find hole size (in air) for .050 dia pin to maintain
 50 ohm impedance.[.050 x 2.300 = .115 dia]