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INDUCTANCE
- Thread starter markg
- Start date
that would be fun for me and a night mare for him.A mono PI coil is easier to do than an induction balance VLF coil, for sure. Also, most VLF's the transmitter coil inductance has to be within about 3% of specification (preferably better), but most PI's easily tolerate a 20% departure from the design spec.
There are engineering formulas that pushing a pencil will get you to better than 20% in a round or oval coil. Anything other than that, you really should buy yourself a cheapie LCR meter. Haven't priced 'em recently but we're probably talking less than $100. Jameco is a good outfit for stuff like that, but of course once you've got the catalog you'll likely drool over a bunch of other stuff too. SparkFun might have an LCR meter kit, but then you'll have to build the kit-- a project you may not want. .......About 3 years ago Texas Instruments came out with an integrated impedance sensor chip which will likely revolutionize cheapie LCR meters, it may be happening already.
There are engineering formulas that pushing a pencil will get you to better than 20% in a round or oval coil. Anything other than that, you really should buy yourself a cheapie LCR meter. Haven't priced 'em recently but we're probably talking less than $100. Jameco is a good outfit for stuff like that, but of course once you've got the catalog you'll likely drool over a bunch of other stuff too. SparkFun might have an LCR meter kit, but then you'll have to build the kit-- a project you may not want. .......About 3 years ago Texas Instruments came out with an integrated impedance sensor chip which will likely revolutionize cheapie LCR meters, it may be happening already.
Thanks Dave, I have a dual scan oscilloscope and plenty of components. I repaired TV's and computer monitors while money could be made, but been out of electronics and rusty. Been metal detecting on and off since 1978 and just a couple years ago bought my first PI. What has really got my attention about the PI is, even though it has limited discrimination abilities, I've been able to detect and recover may good relics that remained silent on all major VLF machines. By that I mean side by side comparisons indicated these targets were masked and could not be detected by my VLF machines. I could elaborate, but I'm sure no one is interested in my stories. Anyway I have a need and a few ideas that can be met with a mono coil.
wow so all VLF coils are within 3% are the best ones on the dot as in perfect and how long can they stay there ?? for ever? which ones are better ones in solid resin or the other hollowed ones? guessing the resin ones, but that's a guess.
so how does one get these things on the dot moving wires around ??
seriously I have no idea , love to learn though so might move over to Texas
that's probably not going to happen couldn't even make the shop today 
good luck with the PI markg sounds like fun or is it stress
AJ
so how does one get these things on the dot moving wires around ??
seriously I have no idea , love to learn though so might move over to Texas
that's probably not going to happen couldn't even make the shop today good luck with the PI markg sounds like fun or is it stress
AJ