Coil Wire / Lengths

[mdiede57]

I am considering trying my hand at making a coil. At this time, all I have handy is CAT 5 cable. Has anyone attempted using CAT5 cable for coil wire (with the insulation left on)? Has that worked?
and estimated, can someone give me a clue as to how much wire a 7" D roughly say, 100 turns, would take?
I'm just considering using it, would it work ?
How much wire length would I expect to use in different sizes of coils, 7", 4", 10", 12". i'm not asking perfection, just a caculated guess as to what to expect.

Thanks

[Kev]

Hi,
I've tried Cat5e cable and it works very well, especially the stranded type. To help maintain high speed digital waveforms they often use teflon as the insulator which has very good dielectric performance. The problem is the kinks in the wire, and getting a neat bundle.

Looking at your second question, I see you want 100 turns so I figure you're using it for a VLF coil, whereas I used it for an early sample PI. It should be fine for the TX on the VLF but over kill for the RX.

To find the length you'll need, I guess you mean DD? Multiply the diameter by pi to get the circumference, halve that and add the diameter, that's roughly one D of the DD, then multiply that by the number of turns you need.
i.e. 7 x 3.14159 / 2 = 10.995
10.995 + 7 = 17.995 inches per turn
17.995 x 100 = 1799.5 inches
which rounds up to 150 feet for each D of the DD

Cheers
Kev.

[mdiede57]

Kev,

when you use cat5e, you strip the individual wires to seperate them, correct? Since I know where I can find cat5 easier than enameled wire to the bulk needed, I thought I'd try it. Where would I find a good enameled wire supply?

[Kev]

Hi,
Yes you untwist the twisted pairs, and try to remove the kinks by pulling it round a wooden chair leg or the like.Because you've got 8 wires in the bundle you could use a 20 foot length and solder the wire lengths together to make the 150 feet you need. File the soldered connections down and insulate with tape.

I scavenge enamelled wire from old transformers. The high current low voltage ones are best for wire around 18-20 awg etc.,

Cheers
Kev.