[Hallicrafters] SR-150 Filter adjustment

[Jim Liles]

Hi Jim:
The filter on the SR-150 is a 2.7kc filter with a shape factor of 2.  You can use the S-Meter and tune through a signal, adjusting the terminators as you go for a flat response.  An alternative is to sweep it but it will take but 5 minutes to manually get it right without sweeping.  Switch from USB to LSB and see if there is a distinct difference in pitch.  If so check the carrier crystals for 1648.1kc and 1651.7kc and adjust them.  Even if they are off a bit, they are usually not the culprit.  Tune through a carrier and check whether the filters pass band is 2.7kc at the 6db points and ripple is not greater than 3db.  Never overlook the possibility that the other guys radio has a problem.  What level is the SR-150?  If you need a phone conversation 847-571-8420 --- Kindest regards Jim K9AXN