New cap test run
From: fxphoto [SMTP:fxphoto-at-centuryinter-dot-net]
Sent: Thursday, June 11, 1998 1:45 AM
To: Tesla List
Subject: Re: New cap test run
Congratulations! It sounds like you are back in business again. I am glad
to hear your problem with the safety gap has been solved.
>Well, I fired up the coil last night with the second .025 mfd cap in parallel
>with the first - for a total of .05 mfd. The safety gap across the caps was
>set to .50". I had calculated best tune to be at turn 8.0. It actually is at
>turn 8.5. With 3.3 ohms of resistive ballast in series with a 5000 watt
>variac used as inductive ballast, I had 28 amps of primary current and primary
>pole transformer input voltage of 200 volts. The system ran good with best
>discharges to a grounded wire of about 72".
>I tried changing from 3.3 ohms to the new 2.4 ohm resistor array and at max
>power the system was some what erratic. Primary current was 35 amps bouncing
>up to 45 amps. Switched back to the 3.3 ohm resistors and changed the variac
>tap from the 240 volt output to the 280 volt output. What a difference - we
>had long sparks all over the place. I had a wire extending about 2.0" off one
>side of the toroid, aiming toward a grounded wire target. From this point, I
>had 75" plus sparks to the ground wire but also had multiple breakouts all
>over the toroid, some as long as the ones leaving from the wire. Had several
>hits to the strike rail, must have had a couple into the primary also since
>the main safety gaps fired a few times. Primary current was 35 amps with the
>transformer primary voltage at 250 volts (8.75 kva). Also had hits down to the
>concrete driveway. This is the first time this coil has had strikes that hit
>the earth. The cap safety gaps never did fire! This is great as that was my
>major problem a month ago.
>Based on the big increase in performance gained by going to the 280 volt tap
>on the variac, it kind of makes me want to open up the pole transformer and
>find the next higher voltage tap - maybe. Next run I will try using both
>toroids, the 40" on the bottom with the 33" raised up above it about 12".
>This works good on my smaller coil to keep the sparks from hitting the
>I know there are several other 6.0" dia coils out there. What kind of
>performance have you achieved? My secondary winding length is 27.6" so I am
>getting sparks that are 2.7 times as long as the secondary.
>Finally happy in Spokane, Ed Sonderman