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i want to wind GDT, and i saw pictures of steve´s wards drsstc, where he was using UTP cable from LAN networks. I also have one (but i have 2 wires twisted, not all 8 but allocated to "twists")
how can i know the number of turns, if the core is good etc...? Or rather i should buy chokes, unwire it and wire again?
Thanks ! (sorry for english i dunno how to write that :(
Registered Member #538
Joined: Sun Feb 18 2007, 08:33PM
Location: Finland
Posts: 181
You cant use choke cores because they are made from powdered iron which is very lossy at higher frequencies, you need proper ferrite. You want a ferrite core with a high Al value to get low leakage inductance.
Theres a couple good resources on SSTC GDT design, thedatastreams GDT design guide: And Jan Wagners notes on GDT design:
Btw. I dont think this has anything to do with high voltage.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
Mestre Racerxdl wrote ...
How about using some EE Cores of computer PSU to do the GDT? Someone as already tested it?
Works OK. Boil the transformer for at least 5 minutes, then pull the core halves apart as much as you can (using pliers/kitchen gloves etc.), be careful not to crack the ferrite. If it won't come apart, boil another 5 minutes. When putting back together, make sure there is as small gap in the core as possible, otherwise the magnetizing inductance will go down and the transformer will draw more current unloaded.
i thought you ment toroidal cores... i use that one, but i dont have anything to compare, only to RF filter core from ground line from CRT (it was worse)
this one looks good and i was using that in several applications (i'll post photo)
//Did you mean those ones???
the big one is "big poppa" used for coilgun charging, the smaller one is original (yet) and color is my current GDT (i dont wanted to put it out of protoboard, so sorry for bad image)
//i tried that trick with boiling water... first i broke some corec, but when i got to the "principle" of doing that right, i suddenly get to heaven:
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How to wire GDT
