two box

[pito]

what you have on Tx coil ?

[kece hon]

Out of curiosity, I made a simplified version as in post #70, it works well, the cola can is detected from 80 cm, the only thing missing is ground balance, I am thinking to adopt it from other schemes, any sugestions welcome.

a little help please Mr PITO
i followed the instruction to build tr locator / 2 box
i used this latest know working schematics
instead of transistors TIP31C TIP32C i used TIP41C TIP42C which are a bit robust

i used 16 mhz quarts which gives me 3.3 khz, i did try 32mhz the obtained coil frequency was about 5 khz= 4891 KHZ
last quartz i put gave me the exact frequency as mentioned in the project =2048hz
both my coils TX and RX when measured using LRC meter gives 7.00 mh
TX= wire diameter is thicker 0.8 mm and coil resistance is 13 ohm
RX= wire diameter is 0.6 mm and coil resistance is 5 ohm


when calibrating ; i put the coils facing each other , beyond 30 cm distance there is no recepetion at all on the RX coil
the obtained results at 30cm on the scope are shown in the picture

Yellow is TX
Blue is reception RX


**problems**
i need more distance than 30 cm ( the advertised distance for two box is greater than 2 meters for big objects)
there is no significant audio change on the headset whenever i put a big object between the two coils or whenever moving them inward or outward

--Question--
can you help me what is it that iam doing wrong ?? Thanks in advance

[kece hon]

I'm on it, I need to finish the coils...

a little help please
i followed the instruction to build tr locator / 2 box
i used this latest know working schematics
instead of transistors TIP31C TIP32C i used TIP41C TIP42C which are a bit robust

i used 16 mhz quarts which gives me 3.3 khz, i did try 32mhz the obtained coil frequency was about 5 khz= 4891 KHZ
last quartz i put gave me the exact frequency as mentioned in the project =2048hz
both my coils TX and RX when measured using LRC meter gives 7.00 mh
TX= wire diameter is thicker 0.8 mm and coil resistance is 13 ohm
RX= wire diameter is 0.6 mm and coil resistance is 5 ohm


when calibrating ; i put the coils facing each other , beyond 30 cm distance there is no recepetion at all on the RX coil
the obtained results at 30cm on the scope are shown in the picture

Yellow is TX
Blue is reception RX


**problems**
i need more distance than 30 cm ( the advertised distance for two box is greater than 2 meters for big objects)
there is no significant audio change on the headset whenever i put a big object between the two coils or whenever moving them inward or outward

--Question--
can you help me what is it that iam doing wrong ?? Thanks in advance

[kece hon]

Hi Carl, Hi Forum,

the discussion about "two-box" detector is reopened... My T/R Locator PCB's for testing have arrived today.

a little help please
i followed the instruction to build tr locator / 2 box
i used this latest know working schematics
instead of transistors TIP31C TIP32C i used TIP41C TIP42C which are a bit robust

i used 16 mhz quarts which gives me 3.3 khz, i did try 32mhz the obtained coil frequency was about 5 khz= 4891 KHZ
last quartz i put gave me the exact frequency as mentioned in the project =2048hz
both my coils TX and RX when measured using LRC meter gives 7.00 mh
TX= wire diameter is thicker 0.8 mm and coil resistance is 13 ohm
RX= wire diameter is 0.6 mm and coil resistance is 5 ohm


when calibrating ; i put the coils facing each other , beyond 30 cm distance there is no recepetion at all on the RX coil
the obtained results at 30cm on the scope are shown in the picture

Yellow is TX
Blue is reception RX


**problems**
i need more distance than 30 cm ( the advertised distance for two box is greater than 2 meters for big objects)
there is no significant audio change on the headset whenever i put a big object between the two coils or whenever moving them inward or outward

--Question--
can you help me what is it that iam doing wrong ?? Thanks in advance

[kece hon]

[]

[pito]

Out of curiosity, I made a simplified version as in post #70, it works well, the cola can is detected from 80 cm, the only thing missing is ground balance, I am thinking to adopt it from other schemes, any sugestions welcome.

[kt315]

1200-1500V pulse and 10-20A in coil. Delta Pulse ))) no wish to answer here more... ended matter for me.

[pito]

simplest two-box .

It is not simplest yet, with TC4422 I have 200 Vpp on Tx compared to 180 Vpp in original 4 transistors design,
on the way 22cm Tx coil with the same EMF strength emission.

Отправлено: 30.05.05 08:57. Заголовок: Re: А зачем в схеме предусмотрены отводы от счетчика? Что-то 120 вольт достичь пока не удается. Спасибо: 0
IRF840 постоянный участник	Отправлено: 31.05.05 06:09. Заголовок: Re: Раскачалось аж до 180 вольт.

[kt315]

I found the answer.
переключатель на плюс - прибор индицирует высокую минерализацию ( все металлы ),
на минус - низкую минерализацию ( пустоты )

it is just experimental device in try to make/get simplest two-box one based on Whites VLF Classic circuit.
this switch is supposed to check in real field conditions. nothing more.

[pito]

I found the answer.
переключатель на плюс - прибор индицирует высокую минерализацию ( все металлы ),
на минус - низкую минерализацию ( пустоты )

[pito]

What for there is switch S1 ?
It is turning upside down the graph and what is benefit of that ?

[pustareka]

https://sevzirfo.narod.ru/trlocator.htm

https://translate.yandex.ru

Simple Deep-T/R Locator ver1.0

This metal detector is designed to search for LARGE objects made of non-ferrous and ferrous metals. The scheme does not provide compensation for the influence of the earth, so you can search only on poorly mineralized soils. Sensitivity to small objects such as shell casings, nails and small fragments is sharply reduced. It is possible to search for voids and inhomogeneities in the soil by the difference in soil conductivity.

The maximum depth of detection obtained in practice :

Sheet of roofing iron 50x150cm - 3m (by air)

Passenger car............................... - 4m (by air)

The detector operates in dynamic mode and does not require manual zero setting. The operating frequency is 2 kHz. The amplitude of the voltage on the transmitting coil is 120 volts. Coils with a diameter of 38 cm of 150 turns of copper wire in enamel insulation with a section of 0.4 mm. Both coils are shielded with foil, a small area of 0.5-1cm is left free from the foil (to prevent the formation of a closed loop).

Diagram of T/R Locator ver1.0 in GIF format............................................ .... GIF 26KB

Printed circuit board T/R Locator ver1.0 in Sprint-Layout 3.0 format.......... RAR 27KB

Design features can be viewed HERE

The finds made with the help of this metal detector can be viewed HERE

[pito]

More simple, L -Tx can be reduced to 30 cm and 180 turns, L- Rx 20cm and 200 turns.

[bernte_one]

Hi Carl, Hi Forum,

the discussion about "two-box" detector is reopened... My T/R Locator PCB's for testing have arrived today.

much succes, hope for a short testing video

[ivconic]

Hi Carl, Hi Forum,

the discussion about "two-box" detector is reopened... My T/R Locator PCB's for testing have arrived today.

Once you finish it; please inform us about your impressions.
Also would be nice to record short video demonstration and put on Youtube.