[R-390] IF sweep alignment

[Tom Frobase]

My usual process to check the filters and the IF alignment on a R-390 is 
to use my network analyzer to feed a signal into the IF amp and take the 
output at the IF output.

I started doing this with 51J series receivers it takes a little over 5 
minutes with the analyzer to align a 51J IF.  On the R-390's, A and not, 
the analyzer provides a quick visual check to see of the IF is working 
as it is supposed to ... tom, N3LLL