SB-102/HW-101 T202 Alignment

[W7AMI]

Jim,

   The SB-102 I have had a problem with the T202 alignment.   When it is 
correct the level of the calibrator should be fairly constant across the 
entire dial.   Mine dropped of considerably at the top end.   It has 
been awhile since I worked on it so the details are fuzzy but here is 
what I remember.  

Remove T102 from the circuit board.
Carefully remove the case from the filter.
Draw a schematic of the filter.  I think there are some inductors and 
three trimmer caps inside.
Solder the filter without the case back in the radio.
Here is where it gets fun.   You will have to experiment slightly 
adjusting the trimmer caps to smooth out the band pass so that you get a 
smooth filter response.   A sweep generator would be a big help but it 
can be done with nothing but the 100 Kc calibrator.

Marking the caps before you start is a good idea.  You can get the 
settings back close to the starting point again if things go bad.
Carefull, the B+ for V5 is on exposed leads in the filter.  You will be 
working is thigh spaces with exposed high voltage.
This is not for the faint of heart.

Good luck.

Terry W7AMI

-------------------------------------------------------------------------------------------
Hello.. Was wondering if anyone had any technical information regarding 
the 8MHz Bandpass filter (T202) used in the 1st IF of the SB/HW series 
of transceivers? What alignment information exists? I have one which 
appears out of alignment. Any technical help would be appreciated..

Thanks. -jim

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