[R-390] 1967 EAC S/N 4998 Cosmos PTO Question

[Larry H]

Gary,  Here's the info you asked for about reducing cap inside instead of removing 1 turn to obtain EP:
After removing 1 turn on the e/p coil, the linearity disk no longer placed the adjusting screws close to the center of the linearity cam on each 25 kc point.  It does not need to be dead on, but close is good.  Must avoid having the transition between linearity screws on the center of the linearity cam.  This will cause erratic frequency at the 25 kc check points due to the play in the linearity gear train.  I tried adding 1pf to the main tuning to move the e/p adjustment to regain alignment, but e/p was just 500 cycles out of reach.  So, had to replace the 1 turn that I removed and add an 82pf N200 in series with one of the two 10pf caps inside.  This reduced the overall capacitance by 1.5pf and this did move the linearity screws so they are close to center at each 25 kc point.
Regards, Larry