Man Fred, I hope you don’t loose that in the move. I for one would very much like to see that. I’m still not convinced that the engineers just simply threw a dart and whatever value it landed on was the cap that they choose to use.
The RF is not simply function of the number of times the points open and close although this being in the audio rang it is imposed on the carrier and we here it at the speaker. The spark generates a multitude of frequencies as it rings down. As you know the spark gap was used in the earliest days of broadcasting to generate a carrier and this is exactly what we are doing with out little spark gap generators in the vehicle. Back in the early days as more stations went on the air, and were closer together the need to assign carrier frequencies became necessary. By then the spark gap had been replaced by the vacuum tube transmitter where the frequency of the carrier could be regulated.
Any cap is going to act as a short to ground for the RF. I would imagine that the size is pretty much determined by the amount of energy that it has to handle. I don’t have an electronics engineering background, just an old mechanic so I have to leave these calculations up to guys like you Justin.
I have been checking a bunch of caps using an HP 4262A LCR Meter, quite accurate and again I am finding them all over the place. And I think I might have mentioned it, he caps from JC were .047uF
Denny Graham
Sandwich, IL
