Re: Failures Specifics

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

In a message dated 11/26/01 3:36:34 PM Pacific Standard Time, tesla-at-pupman-dot-com
writes: 


>
> Original poster: "pjj by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <jjenkins-at-satx.rr-dot-com> 
>
>
> Used 
> Ed Sonderman's tesla excell sheet 
>
> i continue to play w/ it nightly and will keep tring 
>
>
>
> TC – Primary 
>
>                                                 
>
>            Inner Diameter             - 8.25” 
>
>            Outer Diameter            - 14.5” 
>
>            # Turns                        - 7 
>
>            Material (Cu Tubing)  - .25” 
>
>            Spacing                        - .5” on centers .25” between
> the 
> walls 
>
>            Calculated Inductance - 19.8 uH 
>
> <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 
>
> TC – Secondary 
>
>
>
>            Diameter                              - 2.5” 
>
>            Length of Windings            - 22.25” 
>
>            Turns per Inch                     - 36 TPI 
>
>            Gauge                                  - 22ga. 
>
>            Calculate # of Turns           - 777 turns 
>
>            H/D                                      - 1:8.9 
>
>            Calculated Inductance        - 4 uH 
>
>            Cal. Self Cap.                      - 7.1pF 
>
>            Unloaded Res. Freq.            - 939 khz 
>
>
>
> Tank Circuit – 
>
>
>
>            Cap – 
>
>                        Geek Group Variation 3.5 gallon Bucket 14 Bud-light 
> bottles 
>
>                        Measured Value            - .019 uF 
>
>
>
>            Spark Gap – 
>
>                        Static single gap 
>
>
>
>            Transformer – 
>
>                        MOT no protection circuit no doubler 


Paul, 

Some comments on your coil: 

The coupling is probably not as tight as it could be since the inner primary to
secondary clearance is so large.  A "normal" inside diameter for the primary
with a 2.5" diameter secondary would be about 4.5". 

The calculated inductance of the primary should be 4 milliheneries, as opposed
to 4 microheneries. 

With no toroid, and using all 7 primary turns, the tank capacitor calculated
for resonance is .0015 microfarad.  At 1.9 turns on the primary and no toroid
it should tune with the .019 ufd cap.   With a small toroid of say 10 pf, the
resonance frequency goes down to 587 khz and the required capacitor is .0037
ufd at turn 7.  I suggest a cap of around .004 to .005 ufd maximum.  I find
better performance with more primary turns, like 10 or 12 minimum. 

I like to see secondary size ratios in the 1 : 5 area, yours is almost 1 : 9. 
Generally speaking, tall skinny (candlestick) secondaries do not perform very
well.  If you get this thing tuned up, it should provide sparks however. 

Ed Sonderman