Metal detectors PI, VLF, TR, BFO, radio spay finder, electronics device for bee poison

History

Here are presented some of the developments

from Ilia Kanchev

 Metal detector M603

One of the first metal detectors.

It works using the method of comparing of two signals with a same frequency.

The frequency is around 100kHz. The two sine-like signals are converted into rectangular impulses. After that the fronts of the two signals are digitally compared.

The parameters are quite modest.

A coin with a size of 2,5 cm. (1 inch) can be detected at 15-17 cm. ( 6-7 inches).

It can make a difference between metals.

Can be seen on the picture bellow.

Metal detector VLF-210

With far more better characteristics, the next model.VLF-210

VLF-210

It works using the method of measuring the phase difference.

It has two independent channels. The first of them works without making any difference between metals, in order to accomplish a maximum depth, and the second one works in a parallel way and has a function of making the difference between the metals.

Work Frequency - 6,5kHz

Its characteristics  were as follows:

A coin 12mm ( ½ inch) ---------------------------------------- 30-39 cm (12-15 inches)

A coin 25mm (1 inch) ------------------------------------------ 40-50 cm (16-22 inches)

A metal disc 245mm(9,6 inches) ------------------------ ---110-130 cm ( 43-51 inches)

A copper sheet of metal 60x60 сm.(23,6x23,6 inches) -- 200-250сm (78.7-98,4 inches)

Maximum depth of ------------------------------------------------- 270 cm ( 106.3 inches)

Metal detector TR6

The next metal detector that I have developed is TR6

It's a depth metal detector. It works using the method of receiving-transmitting.

The whole body is made entirely of metal. The transmitting and the receiving frame are completely made by metal, too. It is constructed and disassembled extremely easy. It takes around 8 seconds to be assembled. And it takes 5 seconds to disassemble it.

TR6

 Characteristics of the depth on which it works:

Aluminum disc, 8 cm (3 inches) - --------------------------122 cm (48 inches)

Iron pipe , 40 х 3,5 cm ( 15,7 x 1,4 inches)----------------150cm (59 inches)

Aluminum disc, 14 cm (5,5 inches)------------------------- 176 cm (69 inches)

Iron disc, 24,5 cm (9,6 inches) ------------------------------ 235 cm (92.5 inches)

Iron sheet of metal 70 x 80 cm ( 27.5 x 31.5 inches) ---- 400cm (157.5 inches)

Maximum depth ---------------------------------------------- 520 cm (204.7 inches)

Metal detector PI 701

The next metal detector is PI 701

It's an impulse metal detector. It is entirely controlled by a microprocessor.

It has a LCD Display

It is easily home-made, that is its purpose. It is offered as a construction KIT . It can work with a variety of coils.

 From 2,5 cm ( 1 inches) to 100 cm (39,4 inches)

The outside elements for turning-on are shown.

Its main advantage is that it can be constructed at home, it does not require any settings or adjustments and it works with a variety of coils. The coils does not require any additional adjustments, too.

This metal detector is constructed with a goal to achieve a maximum simplicity, without the requirement of any additional settings.

 Depth of detection:

A device for detecting radio-microphone bug transmitters.

Use.

For checking any kind of rooms for hidden radio-microphones.

Technical Information

1        Frequency range - 5 MHz - 2,5GHz

2        Sensitivity at the end points of the frequency range - 0,2 mV

3        Power supply - One 9V battery

4        Distance for detecting a very low signal - more than 15-20 cm.

5        Indication -  Linear-light scale of four LEDs. ( Depending on the number of the lighted LEDs, the distance between the device and the bug can be determined. As much of the LEDs are lighted up, so close we're to the radio-microphone bug device.).

6        One green LED- For very low and unstable signal.

7        Three red LEDs - For a stable signal from the radio microphones device.

Electronic device for extracting bee poison.

The device is to be used in remote outlying regions. It irritates the bees without killing them and it provokes them to set off their poison on a glass. After the poison on the glass dries, it is scraped off the glass. The amount obtained from just a one hive for a day is about 0,5-1,5 grams. The device is power supplied by two AA (R6) batteries.

  How to Make a Metal Detector

(two editions, 10 000 copies)

Archiving Programs for Personal Computers

( 7 000 copies )

Dr. Ilia Kanchev (age 46)

Bulgaria

 ilia_kanchev@engineer.bg