εφτιαξα πηνεια Ω με 0.12 πηνηοσυρμα 32 ποντουσ, με τα τυλιγματα που λεει το σχεδιο, απενεργοπηησα και το κυκλωμα με το 555 και εβαλα ηχειο στο αριστερο ποδι του Τ17 για ηχο μονοτονο, αλλα δε δουλευει, το ανοιγω και χτυπαει συνεχωσ και δε ρυθμιζει απο το 50Κ καθολου να σταματησει ο ηχοσ οπου και να το μηδενισω, αλαξα και συνχνωτητεσ και παλι το ιδιο. τι αλο πρεπει να μετατρεψω για να δουλεψει? το σχεδιο απο το χεαντκιντ ντελουξ το εχω αλλα ακρη δε βγαζω

τσαπι ολλοι θελουν το τοπικο να το κανουν pd,εσυ γιατι κανεις δοκειμες για το αναποδο???

γιατι για τοπικο ειναι καλο και δουλευει!

ποσο καλητερο ειναι απο ενα τοπικο??
η απλα δουλευει….?

για PD δουλευει καλα και ειπα να του κανω υποδοχη ξεχωριστη και με διακοπτεσ που να το γυριζουν σε αλεσ ρυθμισεισ και να περνει και δισκο. το παραπανω προβλημα το ελυσα αλλα δε δουλευει καθολου καλα για τοπικο! αντικειμενο 30χ30 στουσ 10 ποντουσ το πιανει! χα χα! με το δισκακι του pd που ειναι 9 ποντουσ διαμετρο το πιανει στουσ 50 ποντουσ το ιδιο αντικειμενο! αρα τι τισ θελω τισ μετατροπεσ?

ενοεις οτι εφτιαξες πηνιο στους 30 ποντους με τις ιδιες σπειρες που λεει το σχεδιο για το πηνιο των 9 εκατοστων?(εγω νομιζω οτι ειναι μεγαλυτερο παντως.καπου 16 εκ.)
θα πρεπει να χρησημοποιησεις ενα προγραμμα υπολογισμου αυτεπαγωγης,να βρεις ποση ειναι η αυτεπαγωγη του πηνιου που δινει το σχεδιο και μετα να υπολογισεις τις σπειρες για ενα μεγαλυτερο πηνιο με την ιδια αυτεπαγωγη.
:28_1_19:

τσαπι εισαι παλαβος το πιστολι δεν ξαναγινεται τοπικο λογω αλλαγης σχεδιου και συχνοτητας
αφαιρωντας το 555 ουσιαστικα αφαιρεσες τον διαιρετη παλμων και στο μεγαφωνο θα εχης τρελλα σφυριγματα ρευματων
αν θες τοπικο ξαναφτιαξτο οπως ειναι

παρη εχεισ δικιο, απο οτι βλεπω κιεγω δε γινετε ευκολα, το πυνιο το 9 ποντουσ pd ειναι Ω-399 μΗ και το Ο-834 μΗ και αυτο που ευτιαξα το 30 ποντουσ ειναι Ο-4,23 mHκαι Ω-1,92 mH. αν τα κανω 30 ποντουσ και φερω την αυτεπαγωγη απο το μικρο θα δουλεψει λετε?

rider απο 7 μεχρι και 14 ποντουσ να το κανεισ δεν εχεισ προβλημα ότι αυτεπαγωγη και να βγαλει, εγω εκανα το πυνειο το 9 ποντουσ με ιδια αυτεπαγωγη Ω και Ο με ρυθμιστη αυτεπαγωγησ, και εβαλα ιδιο πυκνωτη και στα δυο και μηδενιζει πολυ καλα, το ευρω 30 ποντουσ το επιανε, και γιαυτο ξεκινησα να κανω τα μεγαλα τα 30 ποντουσ, τα εφερα κιαυτα σε ιδια αυτεπαγωγη αλλα τιποτα ομωσ μ'αυτα, και τα εκανα τισ γυρεσ οπωσ λεει το σχεδιο. αν τα κανω 30 ποντουσ αλλα να αφερεσω γυρεσ απο τα δωδεκαρια στο Ω και απο το Ο π.χ. απο 45 και 45 να τα κανω 30 και 30, να φερω αυτεπαγωγη σαν απο τα 9 ποντουσ ενωω, θα δουλεψει αναλογα σωστα?

Καλησπέρα
Το πρωτότυπο το πηνίο το έχεις ακόμα ?
Εάν ναι τότε μέτρα τις αυτεπαγωγές και τις αντιστάσεις των πηνίων του SEARCH COIL S,P,N,T,L & PICKUP COIL K,J,H και φτιάξε ότι κάνεις κεφι…..
Να θυμάσαι ότι το ,πρωτότυπο S-L με 3300 pF ταλαντώνει στους 100 kHz .
Και κάτι ακόμα πρέπει να βάλεις το pot του NULL και τα Q205 &Q206.

εχω και το προτοτυπο αλα ειναι χαλασμενο, και εκοψα καταλαθωσ το πυνιοσυρμα απο το δισκο του Ω καθωσ το εκανα καποτε εγχιριση και δε μετραει τιποτα. παντωσ αφου ξερουμε οτι εχει 100ΚΗΖ συγκεκριμενο πυκνωτη μπορουμε να βγαλουμε αυτεπαγωγη, σωστοσ εισαι και να σου πω οτι δε το ειχα σκευτει αυτο

εγώ θα έλεγα να ανεβάσετε λίγο την συχνότητα του στα 120-130 khz μπορεί να δείτε καλύτερη σταθερότητα και λιγότερη κίνηση (αυτό είναι κακό βέβαια γιατί δεν φτιάχνει καλό αφρό στον φραπέ)

εγω εχω δοκιμασει απο 20ΚΗΖ ΜΕΧΡΙ 1ΜΗΖ και ειναι ολεσ το ιδιο σ'αυτο το ρημαδι, ΔΕ ΠΑΙΖΕΙ ΡΟΛΟ Η ΣΥΧΝΩΤΗΤΑ ΚΑΝΕΝΑΝ ΑΝ ΥΠΑΡΧΕΙ ΔΕΙΓΜΑ, ρολο σημαντικο παιζει η αποκληση εκπομπησ ληψησ γυρω στο 30/100, δηλαδη στα 100ΚΗΖ εκπομπη 70 ΚΗΖ ληψη, αλιωσ δε δουλευει καθολου καλα.

ανέβα λίγο εκπομπή και κατέβα λήψη και είσαι οκ!!! :36_4_12:

110 ΜΕ 60? ΤΑ ΕΧΩ ΔΟΚΙΜΑΣΕΙ ΚΙΑΥΤΑ

123-125 με 65-67

OTI K NA TO KANEIΣ ΑΠΟΣΤΑΤΙΚΟ ΔΕΝ ΓΙΝΕΤΑΙ,,,,,,

A chronological account of the development of
treasure and gold locators from 1830 to 1930.

As all gold hunters know, we are blessed with high-technology instruments to aid our searches for precious metals. Nuggets can be identified in a highly mineral matrix, thus eliminating unnecessary digging of unwanted material, and the Goldspear will locate even gold dust. However, none of these sophisticated detectors appeared overnight, nor was any one man responsible for the invention of metal detection.

THE PIONEER

old prospectorIf any one person could be regarded as the inventor of metal detectors, I will nominate English geologist and mining engineer R. W. Fox. It was Fox who first discovered that electricity will flow through metallic ores as well as solid metal objects. Thus, circa 1830 he devised a simple metal locator which consisted of nothing more than a battery, several metal rods and a suitable length of wire. His first method of detection was as follows: one metal rod would be driven into the earth where the suspected vein of ore was located; it was connected to one terminal of the battery. The other battery terminal was connected to a floating wire. Other metal rods were driven into the ground at several different points and successively touched with the floating wire. Where a spark occurred, it was an indication that metal was present. Circa 1870, this device was modified to two rods insulated from each other in a common probe and connected via battery to a bell and plunged into the earth. When contact was made by metallic ore, nugget or metal pipe, the bell rang, thus indicating the presence of a conductive object.

THE INDUCTION BALANCE
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early metal detectorIn 1879, Professor D.E. Hughes demonstrated to the Royal Society in London his Induction Balance (I.B.). Its purpose was to study the molecular structure of metals and alloys. However, Hughes and his instrument maker, William Groves, soon recognized the potential of the I.B. as a metal locator, and several were supplied to various London Hospitals for locating metal objects in human bodies. The Royal Mint used the Induction Balance for assaying metals and detecting forgeries.

The well- known American inventor George Hopkins modified the I.B. for locating metallic ores, treasure chests and the like. In fact, the Induction Balance forms the basis of most metal detectors we use today.

FURTHER DEVELOPMENTS

On June 21, 1902, the London Electric Ore Finding Company filed an application at the British Patent Office for an entirely new type of metal detector. This was a very advanced instrument for its time, having a range of one hundred yards. It operated as follows: a bank of batteries supplied a high-voltage, heavy-duty current to a spark generator; its output was chopped by a motorized contact breaker to achieve a signal at audio frequency, which in turn was fed to two transmitter probes driven into the earth. At a suitable distance away, two similar probes were connected to receiving apparatus, and equipotential lines of conducting material (ores or solid metal objects) could be plotted.

detecting drawingThis company also developed an underwater spear-type detector which was used in locating gold bars in the wreck of the LAURENTIC, which was torpedoed during World War 1. This was a discriminating-type detector which could distinguish between gold and other metals. Unfortunately, the patent specifications are very brief and no illustrations are enclosed, hence we lack full information of how this detector worked.

Electric Metal Locating Company of Chicago took a different approach to metal detection, and based their instrument on the Wheatstone Bridge principle with two ground probes as sensors. A similar principle was employed by another American inventor Fred H. Brown who, in one of his patents, actually specifies his detector as being suitable for locating buried treasure.

THE WIRELESS AGE

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With the very rapid development of wireless techniques during World War I, it was only natural that this technique would be adapted to metal locators and prospecting equipment. One of the first pioneers to exploit this technology for locating buried treasure was Englishman George Williams, who was the wireless operator aboard the salvage ship RACER during the recovery of gold from the wreck of the LAUREN TIC. Being fully conversant with wireless techniques, and seeing the somewhat primitive treasure locators available then, he decided he could improve the existing technology by designing a Radio-Locator (as metal detectors were known then).

In the book, "DIG FOR PIRATE TREASURE," the author states that, "Williams had a metal detector of his own invention and used it to good advantage in Panama." This surely must be the greatest understatement ever made relating to buried treasure. Further on, the author goes on to say that Williams "unearthed some wonderful stuff, including gold pots, candlesticks, silver bells and many historical things. A solid gold ball seven inches in diameter with a cross on top and gold leaves underneath."

On January 7, 1928, The London Times newspaper reported that Williams found "a solid gold altar two feet high," while C. B. Driscoll in DOUBLOONS expands the finds list even further. He also describes the Williams' detector as a Transmit-Receive instrument operating at radio frequency. Williams, with his locator, arrived in Panama in July 1925, hence he certainly was one of the pioneers of T-R technique (see author’s note).

At approximately the same period of time, Radiore Company of Los Angeles developed a large-scale metal prospecting apparatus operating at fifty kilohertz.

Circa 1926, SCIENCE AND INVENTION magazine published construction articles under the title, "The Radio Gold Explorer." So we see that even amateur gold hunters were catered to. By the mid-1930's, there was an abundance of gold and treasure locators, the most notables being: the Alpha by George Maher, Terrasearch from Engineering Research Corporation, Radioscope by Goldak, Inc.; and, of course, Metalloscope from Gerhard Fisher. The Metalloscope was undoubtedly the most popular treasure finder of all time having survived in continuous production right up to the solid-state era, hence the M-scopes of the current Fisher line of detectors.

Metal detectors are instruments built to detect the presence of metals, mostly buried in the ground. The most heard about use of metal detectors these days is in the defense field, wherein these sensors are used to detect enemy land mines. The detectors are also used by security personnel, geophysicists and archaeologists.

History of Metal Detectors
During the last decade of the 19th century, scientists from all over the world explored the prospect of constructing a device which could detect metals. It was conceptualized that introducing such a device would help to detect rocks with ore content beneath the surface of the Earth, thus making mining easier.

In 1881, when American President James Garfield was hit by a bullet, a device working on similar concept was used by eminent scientist Alexander Graham Bell to try to locate the bullet. The attempts were however unsuccessful as the detection tool was baffled by the metal bed on which the President was lying.

A radio direction finding system used for accurate navigation was developed by Gerard Fisher in the 1930s. While testing this system, Fisher realized that there was some deviation from the normal trend of the machine, when it closed in on an area assumed to have ore-bearing rocks. He realized that it was possible to design an equipment which could detect the presence of metals by utilizing search coil resonator at a radio frequency. By 1937, he was granted a patent for the detection device, thus becoming the first person to get a patent for a metal detector.

A Polish lieutenant called Josef Stanislaw Kosacki refined the design to come up with a practical detector during the World War II. This heavy detector which operated on vacuum tubes required separate batteries for functioning. One of the most useful equipments in the war, it was widely used to clear the minefields laid by the retreating German forces.

Being an armed forces research operation, the modification of the device into a full-fledged metal detector was kept a secret for about five long decades. Once the concept was out, many firms came up with their innovative versions of metal detectors. Amongst the early manufacturers was Oregon based Whites Electronics, who introduced a detection machine called the 'Oremaster Geiger Counter'.

The induction balance system which worked on the theory of magnetism was invented by German physicist Heinrich Wilhelm Dove many years before the invention of the metal detector. The system was made up of two electrically balanced coils which would get unbalanced when closed in on any metal. The use of the induction-balance system in these detectors made this crude devices more powerful. The development of the metal detector also received a major boost with the development of Beat Frequency Oscillator (BFO) by Charles Garrett. Later, the introduction of the transistor supported the idea of manufacturing smaller and lighter detectors, which would operate on relatively smaller batteries. Though small, these machines were much more powerful than their older counterparts. In the years to follow, the growing demand for this device was tapped by many companies.

Today, metal detectors have become more compact and sophisticated devices. These fully-computerized gadgets use integrated circuit technology which allows the user to set fundamentals like sensitivity to a particular metal, tracking speed, notch filters, etc. The in-built memory chip also stores the collected data for further use. From bulky machines, the detectors have gone through many tests and modifications to become the hand-held devices that we use presently. Metal detectors have come a long way to become power-optimized fast tracking devices

@TSAPI.:

λοιπον, επιδη απο οταν αλαξε το φορουμ δε μπορω να κανω νεο θεμα απο το κινητο, παρα μονο να απανταω σε τρεχων θεματα, δε ξερω γιατι, καποιο κουμπι δε μου εμφανιζει, γιαυτο το γραφω εδω, παρη αν μπορεισ καντο νεο θεμα ή οποιοσ μπορει ασ το κανει. εχω ακουσει οτι με ενα ραδιοφωνο στα μακρα, επιδη ειναι επιγεια τα σηματα, μπορουμε να κανουμε ληψη πανω σε θαμενα μεταλα και να τα βρουμε, χρισιμοποιοντασ ενα σημα απο ραδιοφωνικο σταθμο. το εχει δοκιμασει καποιοσ αυτο? ή ξερει καποιοσ γιαυτο? να σηζητησουμε τι γινετε

Για κατι τετοιο δεν μιλας που περιγραφετε στο παραπανω ποστ?

Και οπως ειπε καποιος με τον οποιο ειχα μια κουβεντα πριν περιπου τρια χρονια.

"The principle for locating metal like radio-devices is in 1926
publication called "The Radio Gold Explorer". I have this info,
transmitter and receiver. Also here a second operator manage the
receiver. I think can be re-build with modern components, because the
old system use vacuum tube (electronic lamp)."

"Καπου" δεν ειμαι σιγουρος γιατι ειναι εμαιλ 3ον χρονων πρεπει να εχω κρατησει και ενα σχεδιο το οποιο ητανε απο το freepatentsonline.com θα κοιταξω αλλα δεν νομιζω να το εχω ακομα.

Κοιταξα δεν υπαρχει πλεον.