[Elecraft] Polystyrene Caps - Elecraft K1

Paul Christensen w9ac at arrl.net
Wed Oct 1 09:07:45 EDT 2008


While I am in the process of making some changes to my K1, I will be moving 
two Polystyrene caps from the bottom PCB up to the top.  The two caps form 
part of the VFO tuning circuit.  The two bottom caps rest closely along the 
steel cabinet and slight flexing of the cabinet noticeably alters VFO 
stability and hence, my reason for moving the caps up to the top of the 
board.  I fully realize that flexing a cabinet while operating is not a 
normal procedure, but I would nevertheless like to optimize VFO component 
placement in the K1.

One end of Polystyrene cap C12 is connected to circuit ground.  Polystyrene 
caps offer the benefit in that one end of the cap represents the outer 
foil -- thus allowing the designer to make use of its inherent shielding 
abilities.  Most Polystyrene caps have a red tracer on one end to designate 
the outer foil lead, but the caps as used in my K1 have no such tracer. 
Unfortunately, the K1 manual's part section does not list the caps' 
manufacturer.  Otherwise, I would refer to a datasheet.

So, my questions is -- can the shielding polarity of the Polystyrene caps as 
used in the K1 be determined by looking at the orientation of the part value 
(i.e., 1200J) as printed on the cap body?  Tnx!

Paul W9AC 



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