Originally Posted by
klevin
The condensers that were part of distributors were to minimize arcing of the points, not for RF interference. OTOH, many cars had special spark plug wires with resistance built in to minimize interference.
Condensors inside the distributors store up a charge to fire the plugs when the points open.
My 1965 Oldsmobile Jetstar 88 with the 330 cubic inch V8 (I miss that car) had a second condensor on the outside of the distributor to shunt high frequency noise to ground. A filter capacitor.
WWII German fighter ace Gunther Rall said his first impressions when flying the early jets was the quality of the radios. Apparently the ignitions on the piston engines seriously interfered with the radios.