[R-390] parts in RF deck - 1st var IF caps

[Larry H]

Russ asked:
In the 1st  variable IF,  the cans-z213-1 -2 -3, there is a 51pf  cap at 213-1.  There is 68pf at z213-2, and  a 51pf  at z213-3.  Why does z213-2 have a 68pf  and not a 51PF?  
thanks folks  Russ.

--------------------------------------------------------------------------------------

I know that the 6C4 accounts for 4-5 pf and the stray capacitance for another 1-2 pf, so where does the other 10 pf come from?  

If you look at the 2nd var IF, you see that all 3 circuits have the same 100 pf cap in each of them and the center one is also isolated with 2 pf caps.  

Maybe the answer is that the 1st var IF input and output is through a short coax - I guess that would add some more cap.

Regards, Larry