[R-390] Setting I-F GAIN ADJ pot and tuning R-F stages on noise

[WD4INP]

Over the years, I developed a simple set of procedures for adjusting the sets used by hobbyists, as opposed to
sets in use by the Navy (which must be done according to the standards):

1. Adjust the RF and IF stages for a peak on front -end noise with no signal input. Use the LINE LEVEL meter. 
    The 0.5 - 1.0 MC band needs termination of the antenna input with a 50-ohm resistor, and then realignment with 
    the ANT TRIM control set to zero and on the antenna to be used. This most closely mimics weak-signal reception. 

   Use the most sensitive combination of LINE LEVEL meter and LINE LEVEL pot possible. Note: as long as R-F input
   levels don't exceed about 10 µV (as with front-end noise), the set can be aligned with the FUNCTION control set for "MGC."

2. Set the I-F GAIN ADJ pot for deflection of the LINE LEVEL meter to "100," with the LINE METER set to "+10," and the
    LINE GAIN pot set fully clockwise. This also provides a rough check of the deterioration of tubes over time.
  


Charles A Taylor, WD4INP
   Grifton, North Carolina