best coil for baracuda?

[jladre]

You can used ordinary pot underwater up to 2 meter depth..why you guys don't make a pressure test on ordinary pot so that you will see that it will work.

[homefire]

Why not just do it right ? http://www.potentiometers.com/select...fm?tab=HexSeal

[kt315]

[6666]

[ATTACH]38334[/ATTACH]

That global shipping you have highlighted is a rip off and nobody should use it.
Ask for normal post office shipping or you will not buy the item.

[Altair]

I am ready to spray graphite inside of my coil housing, just a big doubt I have: how many spray pass have to put for best result? Is one enough or not?
Please a little bit help, thanks!

[kt315]

crosslinked to
http://www.geotech1.com/forums/showt...ax-good-enough

[kt315]

Andrej Schedrin

[kt315]

https://discogslabs.imgix.net/biblio...auto=compress&

one from his books

[nonkapo]

Few more questions about the coil for Bara. Taken directly from Geotech coil database here are the parameters :
Barracuda 8" 545uH 1.24. I read that a 15 inch coil was also offered, hopefully with the same parameters? Now what bothers me since original design was with Darlington how accurate are these induction and resistance for the MOSFET? I read many topics about how tolerant the Cuda is about the coils but still curious. On few places i so 450uH with more or less same resistance. So please do not curse me why i'm asking again.
Thank you.

[waltr]

Few more questions about the coil for Bara. Taken directly from Geotech coil database here are the parameters :
Barracuda 8" 545uH 1.24. I read that a 15 inch coil was also offered, hopefully with the same parameters? Now what bothers me since original design was with Darlington how accurate are these induction and resistance for the MOSFET? I read many topics about how tolerant the Cuda is about the coils but still curious. On few places i so 450uH with more or less same resistance. So please do not curse me why i'm asking again.
Thank you.

Typically the coil is not critical on a PI detector.
Most run fine with coil L of 300 to 500uH.
Coil resistance is also not critical with most lower current PI detectors (under a few Amps).

I have found that if the coil R is too lower the detector can be unstable. If this happens then simply add some R in series with coil.
This is also helpful for shorter TX ON pulses since it seems best to have the coil current almost level off during the TX on period and series R helps this since it lowers the coils Tau [Tau(sec) = L/R].

[nonkapo]

Thanks. So there is no benefit trying to match exactly the original specs of the coil. Will make one smaller for smaller items and that's all.

[kt315]

do not pour by epoxy the winding. thats MAIN rule for to do right fast coil.
leave a big air gap between the winding and a housing. i use a paper rope and after wind scotch tape above.
it gives me 3-4mm of the air gap.

[Tibuck19]

like I mentioned before not all options are equal, Personally for the Surf PI and the Cuda, I made few Mono loop coils at 320uH with 22awg to 24awg, None of the PI coils I made have been shielded, they are all filled fiber glass resin with a UV accelerator additive in it for a very fast low heat set time. I haven't tried what Kt mention of leaving a air gap around the coil loop, Might help but seems like extra work to me, As for my coils, On average, the coils diameter matches what coil depth will search, Example: the 6 inch coil has a search depth 6.5 and the ten inch is 10" search depth. But I only have made 6 or so fully finish coils that I use, Kt Probably made a ton more finish and working coils then I do ! might be wise to try his method out also.

[waltr]

like I mentioned before not all options are equal, Personally for the Surf PI and the Cuda, I made few Mono loop coils at 320uH with 22awg to 24awg, None of the PI coils I made have been shielded, they are all filled fiber glass resin with a UV accelerator additive in it for a very fast low heat set time. I haven't tried what Kt mention of leaving a air gap around the coil loop, Might help but seems like extra work to me, As for my coils, On average, the coils diameter matches what coil depth will search, Example: the 6 inch coil has a search depth 6.5 and the ten inch is 10" search depth. But I only have made 6 or so fully finish coils that I use, Kt Probably made a ton more finish and working coils then I do ! might be wise to try his method out also.

Same here. These simple coils do work which is why I recommend doing a simple coil to start. Much easy to make and will get your detector going. Later you can try other coils but testing and evaluating each is a task to decide if it is better or not.

Tibuck19,
I see a Bank of Canada Token as your avatar.
I found one of these a few days ago. Its an 1850 half penny token found on a local soccer field.

[Tibuck19]

Tibuck19,
I see a Bank of Canada Token as your avatar.
I found one of these a few days ago. Its an 1850 half penny token found on a local soccer field.

Really! over there in the USA ! That great! guess the boarders were not so hard to pass back then hahaha, I found this one over the summer with the TGSL, but its a One Penny not a half penny, it measures 33mm across and Wight 15grams, They are a great find as its a good indicator no one has detected where its found, as it rings up good! but don't get excited about its value lol I had it praised, it is considered very good condition, but because its a bank token and not actual money, its only worth 10$ CAD but for a bit of copper buried in the ground for a 168 years! Still a great find. Congrats I know I was really happy to find mine!