Start TGSL built

[BKY1337]

I added one more winding at the outside of the glued coil. Its still about 17 kHz at Tx (The Rx coil).
I have a slight signal at 19-20cm but its not enough for me.

I have them connected without cable , just the bare wires. I have a lot disturbing signals and i think they go away with the shield.
But does the shield change the detecting depht?

I have about 50cm with a coke can.

[BKY1337]

Now i changed the coils and got about 20cm good signal with an 1 euro coin, and 25-27 slight signal.
I think i have mixed up the two coils. Or maybe not, im not sure.

I need to make a new one and i hope i will reach 30cm good signal.
Or maybe shielding is enough.

[BKY1337]

Damn i mixed up the TX and the RX coils all the time in my posts.

The problem is that my coil with 98 windings has a higher frequenzy than my coil with 107 windings.
But i need less frequenzy. Then i think the 98 turns are wrong.

[BKY1337]

I forgot that the frequenzy from the receiver coil changes when i move/null them.

[ripsdevala]

Make sure, freq near
Tx 14.5khz
Rx 13.9khz
Dont look anything, then null, the shape of your coil will determine the lowest nulling. But what i read from the tgsl thread even if not get lowest mV, some of member just make it deep enough. The problem with mine is only coil housing, too heavy without vacuum forming.

[BKY1337]

Damn i was totally wrong. You are right.

14,5 kHz
and
13,95 kHz at the same Tx connector.

Now i have two coils with wrong kHz 15,88 and 16,16kHz.

But i made them both as described with 107 and 98 Turns. This is wrong.

107 Turns = 16,16 (16,04)kHz


13,95 kHz = 123,49 Turns Rx Coil
14,5 kHz = 118,8 Turns Tx Coil

This is way more than described.

[BKY1337]

The resonance 15,88 was wrong, it was about 17 kHz for the 98 Turn coil.

I will make a new one with 124 Turns and then i will remove turns until i get 13,95.
Same with Tx coil 120 Turns and then remove till 14,5 kHz.

I have used the Template from the PDF but its totally wrong.

[ripsdevala]

Don bowers pdf is a good reference, all depends on winding, thickness, and shape.
Lower khz is better than higher, so you can decrease the winding to get proper khz.

Capacitor value adjusting can be use to get proper khz if the winding is already permanently glued.

I hope you have success with it, cause im not get 30cm clearly. IDK

[BKY1337]

Yes but you wont get a lower frequenzy with less windings, as described in the pdf.

I hope i have enough enamelled wire left, i had 125 g and made two coils.
Looks like its enough for two new ones. If not i will go the capacitor way.

Thanks for your help guy!

[BKY1337]

Okay, i made a new one with 125 Windings. It runs with 13,74 kHz now. Was over 14 before constraining with 124 Turns, then i added one more and
constrained. Maybe 124 Turns is enough.

But now my enamelled Wire is empty.

I have 3 coils: 16,1 kHz, 17,1 kHz, 13,74 kHz.

Can i change the capacitor for the 14,5 kHz Coil and use the 16,1 or the 17,1 instead?

Or is it better to add more Windings at the outside of the constrained coils and constrain/glue them again.

Which capacitors do i need? Both of them?

[BKY1337]

Now i have two coils, one with 13,74 kHz and one with 14,47 kHz.

But i have nearly the same results.
Maybe a bit better as before when good nulled.

But only a slight signal at 30 cm with a 1 Euro coin. Detector detects my hand. Signal before was with coin in the hand.
Now its 30 with the coin at the end of a ruler.

But its not shielded and not glued and epoxied.
I think i will lose a little bit depht with shield.

[BKY1337]

Does it matter which end from the coil is connected to a port?
Can i change Start and End from the coils?

[Hyena]

No, you can not.


Start Rx start and Tx start has its own cable. End of Tx is connected to both shelds. Now there are two options for Rx end (and again you can find this in TGSL thread):


1) Rx end is also connected to Tx end and shields inside coil cover.


2) Rx end has its own cable - for improved performance in wet grass.


When I am winding coils I dont care about it. Then I just connect it to circuit and when you get two signals on each move, just switch Rx start and Rx end...

[BKY1337]

Okay, thanks. Maybe i have switched them. I don't use a cable yet.
Just bare enamelled Wires.
I had much better Results with my 16,1 and 17,1 Coils before.
I need to try a cable and changed connection.

[BKY1337]

I have not connected Rx end to Tx end and not to the shield.
But i have shielded my coil with aluminium foil and i lost a few cm.

Im thinking about using the coils without shields.

Now i have about 1m with a pan and 20 with a coin.
It was 30 with a coin before.

And only one coil is shielded now.