Original poster: FutureT@xxxxxxx
A lot of what has been written about 120 bps applies to NST powered
coils. Pig powered coils are more tolerant of different break rates.
You'll want to use a rotary gap with a pig powered coil. A pig
powered coil can be run at 120 bps but a synchronous rotary spark
gap will be needed, and the capacitor value will be more
critical. An async rotary works very nicely on a pig
coil and has the advantage of permitting one to change the break rate
during operation to produce interesting changes in sound and
spark appearance. Break rates from 250 to 400 bps are commonly
used for async coils. Some folks use a fixed async break rate of
around 180 bps.
John