Hi, Gang
While researching the Heath HD-1422 noise bridge, I found
a handy DOS program by KQ6RH designed for the Palomar RX noise bridge,
which will work equally well with the Heath unit.
See:
http://www.antenna-magic.com/Rx_brdg.htm
The allowable ranges of X sub C and X sub L settings
are -70 to +70, representing the setting of the 140pF
capacitor of the Palomar. By using the input
range of to -60 to +60, the 120pF capacitor used
in the Heath HD-1422 is also accommodated by the program.
The program takes the R and X dial settings, and the freq in MHz,
and converts them to impedance in both rectangular
and polar form. The only thing lacking is a further conversion
to SWR, assuming a 50 Ohm transmission line.
73,
Ed Knobloch