TESORO GOLDEN SABRE

[Virdi_248]

[quote = Qiaozhi; 111560] Para tratar de construir su propia bobinas sin la ayuda de un osciloscopio está plagada de problemas, e incluso el intento de construir el PCB TGSL es extremadamente difícil. Yo siempre recomiendo comprar una bobina comercial Tesoro, incluso antes de tratar de construir su propio. [/ Quote]


I do not agree with you. I have experience in welding. I have no experience in manufacturing rolls, I only made 6 or 7 for the metal detector surfmaster and gary and work well.

Tgsl yesterday with only managed to detect up to 5 cm (2 inches) and now got new coils detect the tgsl 18cm (7 "+ -"). As you can see the progress was great. And if I can not learn if you need to use a oscilocopio. The essence of the matter is to make the switch yourself at all costs until the last consequences

[dfbowers]

TGSL #2. I only have about 38 to go to catch up to Ivconic! This one I used TLO71a instead of LM308s and BF245a instead of J107. No difference in performance. Just $11.00 cheaper!!!!

One interesting thing I discovered while testing these.. Don't get your speaker anywhere near the coil!! Since the audio is a harmonic of the operating frequency, you can get some really strange oscillations, even if it's a few feet away. It took me a long time to figure why the circuit would go into these strange audio oscillations. Once I got the coil and speaker well separated, no more problems..

Once it's packaged and you put it into use, no worries though.

[Virdi_248]

One thing if it helps. I made a DD coil 60 back to TX and RX 120 for 0.25 thread if it helps.

The depth (now 18 cm) and discrimination have greatly improved. soon will try to improve more and if I can not use proper and learn to use an oscilloscope

[simonbaker]

I was not referring to @lunamay...

Ok, got confused and needed to clarify anyway...

[simonbaker]

TGSL #2. I only have about 38 to go to catch up to Ivconic! This one I used TLO71a instead of LM308s and BF245a instead of J107. No difference in performance. Just $11.00 cheaper!!!!

One interesting thing I discovered while testing these.. Don't get your speaker anywhere near the coil!! Since the audio is a harmonic of the operating frequency, you can get some really strange oscillations, even if it's a few feet away. It took me a long time to figure why the circuit would go into these strange audio oscillations. Once I got the coil and speaker well separated, no more problems..

Once it's packaged and you put it into use, no worries though.

Interesting what you say about speaker. I have seen feedback but thought it was voltage on rails when speaker sounded. Didn't know that amount of separation needed.

MDs are very hard to experiment with because when spread out on bench all kinds of noise comes in, including from scope probes. Difficult to draw conclusions. You learn best by building same one many times and comparing, especially coils, it seems.

-SB

[Vladimir]

One thing if it helps. I made a DD coil 60 back to TX and RX 120 for 0.25 thread if it helps.

The depth (now 18 cm) and discrimination have greatly improved. soon will try to improve more and if I can not use proper and learn to use an oscilloscope

Check voltage on the Tx coil, must be about 14V pp.

[lunamay]

hi
what sensivity did you get yet?(for 1Euro coin)

[Virdi_248]

Check voltage on the Tx coil, must be about 14V pp.

Now impossible to measure voltage, the multimeter has crashed, it fell to the ground from 3 feet, I have to buy another soon.

I made another DD coil and the coil over a euro coin detected to 26 cm in the air without faraday shield. (RX 100 laps) - (62 laps tx).

If it works right when you put the shield no longer build more coils.

[Virdi_248]

A question about Faraday shield.

Place of connection?

[Virdi_248]

In mineral-free soil.

skip shield?

[Cyclonite]

In mineral-free soil.

skip shield?

Mineral Free Soil, can be Wet Soil, causing higher capacitance interference with the Search Coil. Trees, shrubs, and vegetation can, and will cause problems. HF interference may (will) influence your MD via the Search Coil. HF interference is today a far bigger problem than it was in the past.

Why limit your search Coil to Ideal situations? What will you do when situations become less ideal? You will need two Coils, one with, and one without a Shield. If you want to go deeper, then why not build a larger Shielded Coil?

You will be gaining nothing by leaving the shield off, and loosing all if the situation becomes anything less than ideal. Concentrating on a GOOD Shield, has all the benefits and advantages that you will not want to miss out on.

Regards,

Robert

[Virdi_248]

Finally I put a shield. Problems, approached a finger to 1 mm of the coil or the wire and the detector makes false puffs.

All is well connected.

What's happening?

[dfbowers]

Finally I put a shield. Problems, approached a finger to 1 mm of the coil or the wire and the detector makes false puffs.

All is well connected.

What's happening?

Do you have the shield grounded as documented?

[simonbaker]

connection wires

Hi dfbowers and anyone else:

What kind of wire do you use for connections to pots, switches, and even tx, rx coils? I see red insulated wires. Is it multi or single strand? What gauge do you like?

Stuff I use seems to fight me...

Regards,

-SB

[simonbaker]

Finally I put a shield. Problems, approached a finger to 1 mm of the coil or the wire and the detector makes false puffs.

All is well connected.

What's happening?

magnetic personality, or nice sensitive detector!