[Elecraft] K2 ALC Anomaly Using PTT

Unifiedtx at aol.com Unifiedtx at aol.com
Tue Aug 31 15:13:16 EDT 2004


the ALC anomaly is for real if the KI6WX PN2222A amp mod is installed on the 
KSB2 board.  This was the case involving the three K2s with the ALC anomaly.  
Gary Surrency says that the added PN2222A that follows the U5 NE602 balanced 
modulator overdrives the standard ALC allowing up to 200W on voice peaks.  The 
solution according to Gary is to replace R9 with a 1.5K resistor, and add a 
new resistor of 1K in the base lead of Q1.  Cut the trace between Q1's base and 
pin 6 of connector pin, and insert the 1K resistor across the cut.  Gary 
further says these changes should only be necessary if the emitter follower was 
added after U5 as shown in John's (KI6WX) KSB2 document.
I want to thank Gary for clearing up this ALC thing.  Roy Morris  W4WFB


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