Re: How much does aspect ratio of secondary really matter (is it all about K ...

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FutureT@xxxxxxx 

In a message dated 5/31/06 5:02:45 PM Eastern Daylight Time, 
tesla@xxxxxxxxxx writes:


> All talk of aspect ratio that I can find seems to
> center on K factor, however the K factor I get out of
> JavaTC for this 2.5:1 ratio coil is 0.17, which seems
> "normal" to me.  Any other gotchas associated with low
> aspect ratios?  If I have coupling under control,
> should I be "ok"?
>
> Best regards,
> Aaron, N7OE


Aaron,

There's no real problems with such aspect ratios.
A wide range of aspect ratios work well.  The only
negative possibly is that the toroid might not
overlap the secondary by very much.  More
overlap seems to be better.  I also don't like
too much self-C in the coil itself.  I prefer to see
the C in the topload.  Some tests I did seems to
suggest it works better that way, but as usual there
were many variables in my test, so it's hard to be sure
what was happening.  In any case it's a minor effect.
If you need or want the short aspect ratio for
some other reason, then go for it.

A lot of what's advocated as being *best* doesn't really
make a lot of difference in performance in general.
Generally what's important in coils is; power throughput,
proper toroid size, good spark gap, etc.

John