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Hello, Does anyone know if a salt coil (anti intererence coil) is quieter on the wet sand at the beach? I read one of Regs post's that he had made one. I'm looking into making one for a Sd2100. Thank you, Seb
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I just ordered a K-240C LCR Meter, Scotch 24 tape, 1/4,1/8 poly spiral tape and Feather Lite. I just have to figure out the best type of wire to use for a minelab SD2100. I would like to make a 18" salt coil(anti inteference coil) I guess it is basically figure 8 coil and some different size coils. I guess either 18 ga. tinned copper for the 18" coil. Should smaller gauge wire be used for say a 12" dual field coil? Stephan seems to get the best results from the .02mm enamelled copper wire and Woody seems to do well with the tinned type he uses, I just can't seem to locate it. Seb -
Hi Seb,
Woody sells the tin plated wire on his ebay website. Here is a link to the tin plated wire for sale.
http://cgi.ebay.com/coil-wire-for-mi...item2c4b5c9bab
As for the Salt coil and whether it would be quieter on a wet sand beach, the answer is simple yet complex. If the ground is very level and the coil is held level, the Salt coil should produce a quieter response.
The idea behind a salt coil is half of the coil will give a positive signal on a target and the other half will generate a negative signal. So, if the two signals are equal, there will be little or no signal. This will happen over flat areas where both halves of the coil are equal distance from a similar target, which in the case of wet sand will be the sand itself.
Now, any variation from level will cause a change in signal. So, there is no exact answer to your question but to say it can reduce the signal from wet sand if the conditions are right.
RegComment
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Thank you Reg, I got a pretty good deal on 4 1/2 lbs of 15/38 Litz. I have read where Stephan has had good luck with making his own wire so I will give it a try. I bought a 12" spider coil houising from Hays to try your dual field coil on it. Also a 18x14 housing that I want to try the figure 8 on for use on salt water beaches here in Florida,they are pretty flat. I am thinking of doing this the way you talk about it on another forum where you make two seperate coils and wire them up . I don't clearly understand this way( I am pretty much like a monkey in that I can copy it if you show me but I have very little creative thought on my own) but I hope to ask you more questions when I get to that part. I am going to order some of Woodys coil cable. Thanks again, SebComment
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K-240C and frequency measurements
Hi Seb:Originally posted by seb1008 View Post
This is off-topic, but I have a K-240C LCR Meter. It is a great meter, but I have a problem with mine.
When I measure the frequency of my oscillator across the TX coil (TGSL circuit), connecting the probes across the coil completely changes the waveform and makes it smaller. Apparently the meter is loading the circuit a lot.
I tried with two other meters I have (which have more limited freq range), and they do not change the waveform noticeably (actually just barely noticeable).
The waveform is about 14 V p-p.
When you get your meter, I'd be interested if you could do a similar test to see if the frequency meter loads down the circuit.
Regards,
-SBComment
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Hello Simon, I am sorry I cannot help you, I don't have a oscilloscope. Can you tell me if the K240CS measures Q? I may have to send it back if it does not. According to Stephan it is pretty important to get the Q right. Any ideas on what meter measures Q if this on doesn't? Thank you SebComment
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I am pretty sure the K240C does not have Q measurement.Originally posted by seb1008 View Post
I think this meter does: BK Precision 878A . It is a nice meter. I mention it in this thread http://www.geotech1.com/forums/showthread.php?t=15668.
Regards,
-SBComment
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