[Kenwood] YK-88C Attenuation

[Alan Wormser]

Problem solved!  Thanks to all who responded.  

After quickly checking the 6 solder points of theYK-88C filter, and that the 
jumper was set to CW4, I did the first steps in aligning the receiver - per 
the TS-830 user's manual.  The only slugs that seemed to make a difference in 
volume of the sound coming out the speaker were T2 (RF Board), and L3, L6, 
and L7 (IF Board).  The others (L2, L4, L5, and L11 on the IF Board) didn't 
seem to have any  affect -- at least using the crude methods of tuning by ear 
for max noise (AGC off) or by using the 25 kHz XTAL marker & watching the 
S-Meeter with AGC turned to "fast."

Note that although L12 is mentioned in the Users Manual alignment procedure.  
it is NOT mentioned in the procedure shown in the Severice Manual, nor does 
it appear on any diagrams from either manual. 

So I peaked T2, L3, L6, and L7 and left the others where there were.  There 
may have been some improvement in audio, but it is very slight.  Because of 
the next discovery, I didn't finish the realignment.  

I then looked more closely at the underside of the IF board, where the YK-88C 
filter is soldered.  Using a magnifying glass, I finally saw that the 
problem:  A trace/pad had lifted off the printed circuit board, and slid 
sideways close enough to short out the two pins at one end of the filter.  
So, I reheated the solder and used the tuning tool to shove the pad back into 
position, separating the two pins.

When I tried the TS-830, my attenuation problem was gone.  Now insertion loss 
is less than 1 or 2 dB -- less than 1/2 S-unit according to the S-meter.

Alan N5LF