TGSL 8" Coil

[satdaveuk]

Hi
Just bought a TGS 8" Coil the factory fitted one to try on my TGSL detector.
I only bought it to see if there was much or any difference to my home made ones.
A couple of questions before i get round to trying it out are... Firstly anyone else tryed one, if so what were your results? secondly these coils work on 12khz and Ivconics design works on 14khz so will i need to be changing capacitors at all?, like advise please.

Many many thanks in advance

Dave

[bernte_one]

hello

i use the 9*8 web coil when i compare with my diy coil the original is quit more stable it gives clearer signals distance is lightly higher than diy maybe 3cm

but it was my first diy coil in next months i will try other shape and forms i think i can do something like original

a little tip dont use this self adhesive alu tape it is NOT thin enough it decrease my diy coils ability to discriminate

[satdaveuk]

hello

i use the 9*8 web coil when i compare with my diy coil the original is quit more stable it gives clearer signals distance is lightly higher than diy maybe 3cm

but it was my first diy coil in next months i will try other shape and forms i think i can do something like original

a little tip dont use this self adhesive alu tape it is NOT thin enough it decrease my diy coils ability to discriminate

Hey Hi Bernte
Hope your keeping well
Yes I learned that the hard way disc was crap not matter how coils were positioned, I tryed everything people mentioned on here apart from graphite, the best and most easy to apply is Mylar, its cheap as chips, strong unlike kitchen foil so doesnt keep tearing , and turns your coil into the proper job as its intended, disc works very well.
The reason why I bought this 8" coil was to make sure i wasnt missing out on performance of the machine due to coil errors, I want prefection,The performance in are UK soil here is better than i exspected, but like most of us here we like to push for that extra mile if its out there.
Dont supose you made a circular coil for the TGSL yet, I like to build one but they seem complicated.
Also have you built the TGSLI yet?
The reason why I ask I would like to know if its that much better than TGSL ie is it worth building, or maybe go on to a different project.
Anyway thanks in advance

Dave

[Qiaozhi]

Hi
Just bought a TGS 8" Coil the factory fitted one to try on my TGSL detector.
I only bought it to see if there was much or any difference to my home made ones.
A couple of questions before i get round to trying it out are... Firstly anyone else tryed one, if so what were your results? secondly these coils work on 12khz and Ivconics design works on 14khz so will i need to be changing capacitors at all?, like advise please.

Many many thanks in advance

Dave

If it has a 5-pin connector, then it will work ok with the TGSL. However, if it has a 4-pin connector, I believe the TX coil inductance is only about 1mH.

[satdaveuk]

If it has a 5-pin connector, then it will work ok with the TGSL. However, if it has a 4-pin connector, I believe the TX coil inductance is only about 1mH.

Thanks Qiaozhi
It is the 5 pin type and the inductances are very close to the one we have been building.
all the best
Dave

[Jerry]

Let us know how it works out.

Jerry

[bernte_one]

Hey Hi Bernte

The reason why I bought this 8" coil was to make sure i wasnt missing out on performance of the machine due to coil errors, I want prefection,The performance in are UK soil here is better than i exspected, but like most of us here we like to push for that extra mile if its out there.
Dont supose you made a circular coil for the TGSL yet, I like to build one but they seem complicated.
Also have you built the TGSLI yet?
The reason why I ask I would like to know if its that much better than TGSL ie is it worth building, or maybe go on to a different project.
Anyway thanks in advance

Dave

hello

i think you mean the igsl - no i have not build it but it follows next week depending of getting the order from silverdog

i bought my original coil only for comparing too so i can be sure that there a no mistakes by soldering the pcb

i have thought about building concentric coil too but there is a coil discussion that makes me confusing maybe it could be better to build omega or oo shaped coils the coils from nexus detector have a good performance i have heared

please give info if you found out a good shape

[golfnut]

Id guess that as the Tx oscillator (with external coil) is used for the Rx mixer - it will just work - but maybe a few Khz off from normal.

If you fit it and your worried its say '20kHz' - you may need additional capacitance to bring it back down.

Reverse is true if freq is low.

I guess the problem would then be The Rx coil frequency would need a tweak too - to centre it. Like tuning in a radio to channel.

Steve

[bernte_one]

please help

look here
http://www.geotech1.com/forums/showt...383#post143383

regards bernd

[Farside]

Hi all,

My apologies if this has been answered before...

Everyone seems to be using 0.2 - 0.25mm dia wire for their coils. Is there a reason for this apart from weight?

I'm thinking of using a different guage (0.51mm or 24 AWG) based on some research in inductance outside this forum but has some uncanny similarities...

If it makes not difference then at least I can crank up the power with the bigger guage I guess.

Thanks in advance

[porkluvr]

Hi all,

My apologies if this has been answered before...
Everyone seems to be using 0.2 - 0.25mm dia wire for their coils. Is there a reason for this apart from weight?
I'm thinking of using a different guage (0.51mm or 24 AWG) based on some research in inductance outside this forum but has some uncanny similarities...
If it makes not difference then at least I can crank up the power with the bigger guage I guess.
Thanks in advance

I hope you are only intending to use fatter wire for the TX coil because there is not alot to be gained by using larger wire in the RX.

Before changing the tx coil from ~30AWG to 24AWG you should not only consider more tx power, but also consider added weight. My LTspice calculation shows a coil current increase of about 30%, and MiscEl shows a weight increase of about 400% (that is after I adjusted the number of turns to make up for increased wire diameter to get same uH as before).

Assuming you started with 0.25mm and jumped to 24AWG, your tx coil would increase from 31g to 128g (approx).

The trade-off is up to you but just remember that you would need additional turns of wire to arrive at the same inductance. Maybe 8~9 more turns.

[Farside]

Thank you Porkluvr,

You make a compelling case for smaller wire :-)

I was going to use the 24 on a hunch but maybe I don't need to go on a hunch with my first coils lol!

[nick_f]

Thank you Porkluvr,

You make a compelling case for smaller wire :-)

I was going to use the 24 on a hunch but maybe I don't need to go on a hunch with my first coils lol!

I think thinner wire is preferable because it will make the coil faster. If you put 5cm of 1mm solid copper wire in front of a sensitive metal detector, it will probably detect it. If you do the same test with 0.25mm solid copper wire, it will probably not be detected. That's why some people/manufacturers use litz wire for coils used to detect small gold.
Litz wire is made of many very thin, insulated wires.

Regards,
Nicolae