From: "Terrell W. Fritz"
Date: Sun, 07 Jan 2001 14:34:26 -0700
Subject: [TSSP] Top voltage testing
Hi All, I hooked a scope probe to the top of my coil (finally). The bare coil is: 10.25 inches dia. 30.19 inches long 1000.8 turns #24 wire The base of the coil is 1 inch above the foil ground plane which is split. The top torroid (heating duct) has an 8 inch cord with a 30 inch outside diameter with the center line 42.5 inches above the floor (ground plane). The inductance in place measures (@ 1kHz) 75.1mH. The Fo is 87982 with a Q of 111.2. It has been very dry here lately... The picture is at: http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/bare.jpg For the first test, I hooked the TEK P6015 40kV 3pF 100Meg DC-75MHz probe to the top hung from the ceiling as shown: http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/1000xP1.jpg This probe has a large grounded sleeve in the entire front half and is a big thing so It will definitely load things down. It is built for high voltage safety rather than stealth in E-fields. The top voltage was 53.9 VRMS with 0.707VRMS in (Vo/Vi = 76.24). The Q measured at 92.5 using the bandwidth method with the top voltage measurement. The Fo frequency was 81776 Hz. http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/1000xP1s.jpg For the second exciting test, the probe was positioned off the side: http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/1000xP2.jpg The top voltage was 50.2 VRMS with 0.705VRMS in (Vo/Vi = 71.2). The Q measured at 84.24 using the bandwidth method with the top voltage measurement. The Fo frequency was 79186 Hz. http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/1000xP2s.jpg For the third test, I used a Plain TEK YT5060 60MHz 16.6pF 10Meg 10X probe. http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/10xP.jpg The top voltage was 53.7 VRMS with 0.705VRMS in (Vo/Vi = 76.17). The Q measured at 72.8 using the bandwidth method with the top voltage measurement. The Fo frequency was 70574 Hz. http://hot-streamer.com/TeslaCoils/Misc/PaulNich/Qtesting/10xPs.jpg Not sure what it all means, but these are the mesurements... Cheers, Terry
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.