[Hallicrafters] SX-88 Bulletin: RF Gain Schematic Mistake and Service Info

[WA1KBQ at aol.com]

Hallicrafters Service Addendum Number 94X1351 for SX-88 Receivers
 
C-120 from the high side of the sensitivity control to the chassis is  
deleted.
 
C-148 is added to the sensitivity buss chassis return
 
R-84 was changed from 330K ohms to 15K ohms. 
 
R-84 is incorrectly shown on the schematic in the instruction manual from  
the low side of the sensitivity control to chassis ground. Its correct 
location  is in parallel with C-148 to form a resistor/ capacitor network to  
return the high side of R-80 (sensitivity buss) to chassis ground.  R-80 
connects the high side of the sensitivity control to C-148.
 
Early receivers had C-120 connected to the high side of the sensitivity  
control to chassis ground. This was superseded on later receivers  by C-148 
connected to the high side of R-80. 
 
C-120   10 mfd @ 50V
C-148   250 mfd @ 50V
R-80     10 ohms, 1/2 watt
Early R-84    330K ohms, 1/2 watt
Revised R-84  15K ohms, 1/2 watt