Don,
I may be looking st the wrong diagram but on mine, C5 is associated with L4 which I believe controls the oscillator. L5 on my diagram is an IF transformer. My diagram is for model 986669 which may be for the car version.

Fred


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!