[Elecraft] K2 Noise Blanker & XG1

[Bob Scott]

I have been playing catch up with my K2 (#436) and recently installed  
the A - B mods as well as adding the KAF2 AND KNB2 options.  All was  
well until I added the KNB2 option.  When I added the KNB2 option, I  
noticed that my output levels had dropped.  I then discovered that I  
had forgot to change the resistors on the RF board.

Once that was done, I had improved audio, but the S-meter is reading  
low.  With the KNB2 installed and the pre-amp on, I get about an S3  
when I am tuned to the XG1 generator signal set to 50 microvolts.  If  
I bypass the KNB2 by shorting pins 1 to 6 on J12, I get the full S9  
reading.

I have pulled C8 to isolate the bandpass filter and my S-meter  
readings remain at S3.  Is this normal or might I have a problem with  
the bandpass filter.

Thanks in advance for your help.

73, Bob Scott W4ZY
Woodbridge, VA