Re: Streamer loading effect

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <A123X-at-aol-dot-com>
> 
> To lower the frequency of the circuiut while its running I have two ideas.
> First you could use an extra tuning coil like some people use, but make one
> so a motor could drive it while the TC is on. The problem I see with that or
> just adjusting the primary is that the area where the contact points move
> might spark when its adjusting. Another thought I had was one of those
> variable air capacitors, perhaps with oil instead of air, and have that motor
> driven so when the coil goes on you can adjust the cap from no capacitance to
> full capacitance. Would a variable air cap have enough capacitance to make a
> large enough difference in tuning?

Only if quite large. A big version of a radio tuning capacitor. It is
easier to make an extra tuning coil composed of two sections, one fixed
and other that can moved away, or rotated, connected by flexible wires.
It's also possible to tune the coil by changing the terminal
capacitance,
and there small capacitances make significant difference. For example, 
stack two toroids, interconnected by a flexible wire (at the inner 
side), and mount the upper one suspended by an insulating thread 
(that must be away from the streamers) that controls its height above 
the other. The adjustable extra coil ("off-axis") seems more practical.

Antonio Carlos M. de Queiroz