Re: Terry's Tesla Coil Tuner

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

Original poster: "Mike Harrison by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mike-at-whitewing.co.uk>

On Thu, 08 Feb 2001 07:55:53 -0700, you wrote:

>Original poster: "Bert Hickman by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <bert.hickman-at-aquila-dot-net>
>
>Terry,
>
>Very nice project - simple but it should be quite effective! 
>
>I would suggest a couple of minor revisions to the test procedure to
>improve accuracy of tuning:
>
>1. The secondary measurement should be done with the secondary in
>position and centered within the primary. The primary should be
>disconnected from the rest of the system, and ONE end tied to ground.
>This will give you Fo of the secondary in-situ. 
>
>2. Primary Fo must be measured with the secondary FAR away from the
>primary (10 feet is good... :^)) to make sure there's no coupling
>between the two. Otherwise you may get confusing measurements. Adjust
>the primary inductance so that Fo matches that of the secondary (above). 
>
>Great job, Terry!
>
>-- Bert --

One problem I've found with using square waves for tuning is that you
can get strong responses at harmonics. 

Have you tried using a single-colour LED in series with the 555's
supply? (maybe with a parallel resistor)