Suppression of radio frequency interference at the distributor rotor gap

Generally, for a given spark gap length, lower breakdown voltage of the gap corresponds to a lower radio frequency interference (RFI) level. Mechanisms which lead to the reduction of breakdown voltage at the spark gap by two techniques are discussed. The first technique involves the addition of a pointed electrode near the cathode, while the second technique involves the presence of bulk dielectric material on the cathode surface near the gap. Practical distributor rotor designs based on these techniques for effective RFI control are described.