From: mystuffs@orwell.net (Metlicka Marc)
Date: Sat, 23 Feb 2002 15:51:09 -0500
Subject: [TSSP] Marc's flat coil
All, Flat coil update from Marc M.: I finished unwinding and rewinding the 20" OD coil, It is flat and has very little "lifted turns". I have so far (last night) checked some parameters and have gotten: 20" coil wound with 28g heavy build mag wire, all windings are tight, But in using duct tape as a holding surface, the coil looks kinda like a "brick wall" due to the tape overlaps. I don't think it will effect operation, But it may be note worthy? I have counted 756 turns from a 38" ID around a brass bolt, outward. Sooo: 756 turns 10" radius dc resistance checks at 125.46 ohms Inductance measures at 93.06mh @ 1khz series Q = 4.3 A quick check of selfC measures at 40pf from inside wire outward and 38pf from outside end inward (measured just for giggles) All measurements were made with an esi model 250 DE universal impedance bridge. All measurements were made with the coil 38" from the floor, positioned on an all wood bar stool, 5' clear space on all sides and a ceiling height of 7' 8". There are some heavy metal items against the wall and around the coil starting at 5' away (drill press, hobby lathe, "HUGE" heat sink on an ac drive leaning against wall) so if needed i will clear further. Tonight i will sweep for fo, double check selfC with my general radio capacitance bridge and do some playing around, also try to get Paula to count turns for accuracy (after counting the 3k coils turns twice for me, this may be difficult?), I will post results. Any further suggestions for testing will be greatly appreciated and I will promise to give 110% to get accurate results. Take care, Marc M.
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.