Metal Detector Electronics and Beyond May 1999 Part1     -
  Pipe Nail and Cable Detector   Electronics Today International Vol 28 No.1   (VLF phase metal detector 20khz) -
  How to Build Proximity Detectors and Metal Locators   1972 pp. 121-128   -
  Hledovace Kovovych Predmetov Amaterske Radio B 1990 nr 4 p.122-140 15 plans of different MD, no PIs +
  Hledac kovu Amaterske Radio B 1989 nr 2   TR type based on a LM311 and PLL MD


  Building Metal Locators Tab Books Sept.1986   ISBN 0830627065 -
  Der BFO Detector Elektronik Actuell Magazin II/87 p. 51-56   +
  Detektor metali Elektronika Praktyczna 6/93 pp25-26 TCA 105 based simple MD (Układy z Francji) +
  Prosty wykrywacz metali Elektronika Praktyczna 7/94 pp 61-62 simple crystal controlled BFO (kit AVT-218) +
  Elektronische Spuernase Funkschau 5/1984 p.84-86 Simple BFO type detector -
  Ein einfaches Metalsuchgeraet Funkschau 8/1975 p.131-132   -
    Everyday with practical electronics August 89     -


HE 'Diana' metal detector Hobby Electron. (GB) vol. 3, no 11 Sept. 1981 pp. 10-13 0 refs. (pulse induction) -
  Impuls - Metalldetektor Elrad Sep. 1985 pp. 28-34 simple PI  
  Induction Balance Metal Detector Silicon Chip May 1994   Construction details of an IB detector (Dick Smith kit K-3006) +
  Induction Balance Metal Detector How to Build Gold & Treasure Detectors, by ETI 1981 (in ETI in May 1977) p. 22-27 Project 549, DD coils +
  Kabelsuchgeraet Funkschau 4/1972 p.121-   -
  Metall-Suchgerat Elrad 549 (?) 7 pages TR DD -
  Metal detector Everyday Electronics May 1987   TR type based on a LM311. Good description of how detectors work. Interesting explanation of the permeability of targets +
  Metal Detector - high performance and Simple Construction Elektor November 1981 p.4-11 discriminative IB with PLL, no coil's details +
  "Metal Detector" in Electronic Circuit Manual McGraw Hill 1971 p. 420   -
  Metal Detection Practical Wireless Jan. 1979 p. 35-41 reviev +
  Metalsuchgeraete Funkschau 14/1981 p.50-54 Good basic review about various types of metal detectors. No information about modern discrimination methods. (thanks IVARS) -
  Metallsuchgeraet aus dem Baukasten Funkschau 3/1970 p.77-   -
    Popular Electronics February 1969      
    Practical Electronics October 1988      
  Prospector Metal Locator Electronics Australia Nov 1979   Dick Smith Kit cat. K-3504, simple BFO +
  Prosty detektor metali Elektronika Praktyczna 6/1998   one-generator MD, TL071 based (see Penfold) -
  Prosty wykrywacz metali Radioelektronik 11/1989 s. 31    
  Pulse Induction Metal Detectors Published By Protovale London      
    Radio Electronics November 1967      
    Radiotechnika 1997   description of a PLL metal detektor, Hungarian magazine -
  Schatzuche mit Elektronik Elektronik Actuell Magazin II/87 p. 42-50 detailed description of a crystall controlled PI +
  Treasure Locator Everyday Electronics Oct 1977 p. 58-63 BFO type +
  Wykrywacz metali Radioelektronik 4/90 s. 31    
  Detecteur de metaux a PLL Electronique Practique 8/94 8 pages   +
  Wykrywacz metali Heathkit GD-48 Wybrane układy i urządzenia półprzewodnikowe   p. 255-257  transistorized TR +
  Determination of Depth of Shallowly Buried Objects by Electromagnetic Induction IEEE Transactions on Geoscience & remote Energy Jan. 1985 vol. GE23, #1      
Abbas H J; Brewster R L

The detection and location of foreign metal objects in conveyed products Trans. Inst. Meas. & Control (GB). vol 8, no 2, April-June 1986. pp. 76-84, 12 refs.   -
Allen Lee, Wait Phil A 'Discriminating' Metal Detector How to Build Gold & Treasure Detectors, by ETI 1981, ETI Dec 1980 p. 11-21 Project 1500, IB, search head available at Altec Instruments +
Anglin M E C-MOS twin oscillator forms micropower metal detector Electronics (USA) 22 Dec. 1977 vol 50 no 26 pp. 68   -
Atkinson, R J C Resistivity surveying in archaeology The Scientist and Archaeology (Phoenix House, London) in Pyddoke, E. (ed.) 1963 1-30.    
Barrington A. E. Technical evaluation of metal detectors for.. Cambridge, MA Transportation Systems Center 1972 5 leaves; 27 cm This document arugments the classification and technical evaluation of Commercial Metal Detectors presented in Report -
Barrington A. E. Engineering report on surveillance techniques for civil aviation security Cambridge, MA : Transportation Systems Center 1971 119 p., 27 cm.    
Bean C. P. DeBlois W., Nesbitt B. Eddy-Current Method for measuring the resistivity of Metals Journal of Aplied Physics Vol. 30, No12, Dec. 1959 p. 1976-1980 theoretical paper (P.I. method) +
Beck Robert Earth Resistivity Meter Everyday with practical Electronics January 1997, February 1997 p.12-21, p.102 - 104 surveing by means of 4 electrodes +
Beck Robert Miernik Rezystywności Gruntu Elektronika Praktyczna 5/97, 6/97 p. 9-15, p.15-18 pomiar elektrodowy +
Becker, H, Archaeologische Prospektion, Bayerisches Landesamt fuer Denkmalpflege, Munich 1996      
Beeler C. Finding burried Stuff Rad -Electronics April/1966      
Benrey, Ronald M. A Treasure Finder You Can Build Popular Science July 1966      
Bierestowski Rafał Inteligentny wykrywacz metali Praktyczny Elektronik 11/98 p.7-9 one-generator PIC 12C508 based, no code +
Biernacki Zygmunt, Borowik L., Janiczek R. Krytyczna ocena indukcyjnych urządzeń wykrywających wtrącenia metaliczne Materiały XIV MKM Częstochowa 1979     -
Bindley Keith Find Some Trasure or Avoid tragedy - Turn your tranny into a metal detector ETI January 1989 p. 138-141 a generator that turns a radio into a metal detector +
Borgwardt C. ODIS - Ordnance Detection and Identification System Workshop on Antipersonnel Mine Detection and Removal Lausanne June 1995 74p (LAMI-EPFL, CH-1015 Lausanne,  
Brdulak Jerzy Wykrywacze Metali Młody Technik 8/78 p57-65 BFO +
Brighton M., English M. J. Calculation of Optimum Spacing for a Three Coil Axially Symmetric Metal Detector Electronic Letters IEE Vol. 29 No10

Brockett R. C. Taking A Closer Look At Metal Detector Discrimination by White's Electronics     good practical book for detectoprists, no plans, no theory +
Brockheysen A Practical Metal Detector Electronics Apr. 1938 pp. 17-19    
Burgos J. Metal detectors. II Rev. Esp. Electron. vol 30 no 344 July 1983 pp. 34-6 Spanish, 0 refs. -
Butler T. Metal Detection testing provides protection for consumers and machinery Sens. Rev. 1991, 11, (1) pp. 10-14    
Calvert, Frederick H. Simple Metal Locator Electronics World July 1961 p. 73    
Candy Bruce Minelab's New Super detector: The SD2000 Australian Gold &Gem Treasure   p. 4-8, p. 38 short description of how SD2000 works (in layman terms) no drawings +
Carr Joseph J. Experimenting With Magnetic sensors Electronics Now June 1998, July 1998 p. 56-60 and 72, p. 49-52 experiments mostly on FMG sensors by Fat Quarters Software +
Charles T. The ASDET ASEA Journal Vol. 31 No. 7 1958 pp. 98-105    
Clark A. Seeing Beneth the soil. Prospecting methods in Archaelogy Batsford 1990   ISBN 0-7134-5858-5  
Clark, A J, and Haddon-Reece, D, An automatic recording system using a Plessey fluxgate gradiometer, , Prospezioni Archeologiche 7 1972 107-114.    
Clarke John A Metal Detectors for Metal Objects Silicon Chip May 1998 p. 36-40 4011-based BFO +
Coccioli R. Silvester P P .     Shape sensitivity of metal detectors.   IEEE CEFC '96. The Seventh Biennial IEEE Conference on Electromagnetic Field Computation Conference Title Okayama, Japan. 18-20 March 1996.   pp. 318, Author Affiliation Dept. of Electr. Eng., McGill Univ., Montreal, Que., Canada.    
Colani C. Utylization of magnetic viscosity effect in Archaeological Prospection Nature No 5069     -
Colani C. A novel metal detector using a pulse procedure for large areas with electronic object analysis and detection Frequenz (Germany) vol 22 no 19 Oct. 1968 pp. 300-5 theoretical paper (in German) +
Colani, C. A New Method and Wide-Range Apparatus for Locating Metal Objects in the Ground, Fresh Water & Salt Water Prospezioni Archeolog 1966     -
Colani, C. A New Type Of Locating Device Archaeometry vol. 9 1969     -
Corbyn J. A. Pulse Induction Metal Detector Wireless World Mar. / April 1980 pp. 40-44. lot of theory, unusual PI +
Costa A A detector for embedded conductors Rev. Esp. Electron. vol 30 no 341 April 1983 pp. 44-5 (Spain) 0 refs. -
Crone Robert and David Twin Loop Treasure Seeker ETI September 1989 p. 42-47 simple P.I. +
Czipott P. Pulsed Operation of a Superconductive Electromagnetic Gradiometer IEEE Transaction on Magnetics Vol.27, No.2, March 1991.     -
Das Y; McFee J E; Chesney R H, Time domain response of a sphere in the field of a coil: theory and experiment IEEE Trans. Geosci. & Remote Sensing vol GE-22, no 4, July 1984. pp. 360-7, 21 refs.    
Dawson Colin Beachcomber Metal Detector Electronics Australia Dec 1984 p. 100-110 Discrimination IB MD with DD search head +
Doll et al. Vehicular Mounted Mine Detector Electronics Jan. 1946 pp. 105-109 detailed plans (tubes!) +
Fischer Hans-Joachim, Schlegel Wolfgang E. 'Transistor- und Schaltkreis- technik' german (GDR) book 3.Auflage 1987 p. 292-294 described a Sowjet metal detector (MI-2) including schematics, pcb and tuning instruction (6 pnp-transistors only).  
Flind Andy E. E. Buccaner Indusction Balance Metal Detector Electronics Projects No. 1 pp 103-108 details of aTR with DD coils +
Flind Andy Magnum Metal Locator Practical Electronics August 1980, Sept. 1980 p. 51-57, p.52-55 Construction details of an IB detector +
Gallagher R. All about metal detectors Radio -Electronics Nov. 1980      
Garrett C. Modern Metal Detectors, Revised Ram Publishing Co 1991   a few very simple block diagram, all for layman and hobbiest  +
Garrett, C. Successful Coin Hunting Ram Publishing Co. 1974 pp. 171-173, 189-192.   -
Górecki Piotr Detektor metali Elektronika dla szystkich 1/96 pp 26 - 28 simple one-generator MD (kit Vellemana) +
Górecki Piotr Wykrywacze Metali Elektronika dla Wszystkich 4/5 98   overviev, no plans +
Gray J . Development of an advanced industrial metal detector instrumentation.   Comput. Control Eng. J. (UK). vol 5, no 3 June 1994. pp. 117-20, 2 refs.   Dept. of Electron. & Electr. Eng., Salford Univ., UK. -
Gregory W.D. Materials identification by dielectric and metal detection Washington DC: Georgetown University April 12, 1977". 12 p. 27 cm. Report to the Interagency Working Group, Presidents Commission to Combat Terrorism,  
Griffiths and King Applied Geophysics Pergamon Press 1965      
Griffiths, D H, and Turnbull, J, A multi-electrode array for resistivity surveying, First Break 3(7), 1985 16-20.    
Guelle Patric Detecteurs de tresors, Editions Techniques et Scientifiques Francaises Paris 1982 book detailed duscussion on MDs, sonars, Hall effect magnetometers, many simple plans with construction details ISSN 0153-0984 -
Guelle Patric Metaldetektoren und Schatzschugerate Selbstgebaut - Viele praktische Gerate zur Suche im Freien, im Haus und Wasser Telekomos Verlag Stuttgart 1984 118-page book detailed duscussion on MDs, sonars, magnetometers, many simple plans with construction details ISBN 3-440-05317-2 +
Haigh, J G B, and Kelly, M A, Contouring Techniques for archaeological distributions, Journal of Archaeological Science 14, 1987 231-241    
Heiland Geophyscal Exploration Prentiece Hall Inc. NY, 1940      
Hentschell Eddy Current Comparators ACCO Jun. 1972.      
Hesse, A, Jolivet, A, and Tabbagh, A New prospects in shallow depth electrical surveying for archaeological and pedological applications Geophysics 51 1986 585-594.    
Hobler M. Badania fizykomechanicznych własności skał PWN Warszawa 1977.      
Hubner R Electronic cable location instruments Electrotechnik. vol 28, no 1 Feb. 1977. pp. 53-8 (Switzerland) 0 refs -
Huggard L. Houndog Elementary Electronics Sept/Oct 1980 p. 25-27 One IC (LM386) DD metal detector +
Hugo G. R., Burke S. K. Impedamnce changes in a coil due to a nearby small conducting sphere J. Phys. D: Appl. Phys. 1988/21 pp. 33-38   -
Janeczek A. Prosty wykrywacz metali Elektronika Praktyczna 7/94      
Janeczek A. Prosty wykrywacz metali Radioelektronik 9/84 s.5    
Janeczek Andrzej Wykrywacz Metali Radioelektronik 6/86 s. 26 simple Two-box (nadajnik - odbiornik) +
Justat J., Tkaczyk Z. "Wykrywacz metali" [w]: Układy elektroniczne w praktycznych zastosowaniach WKiŁ Warszawa 1983.   off resonance +
Juzow W. I. Gołosow A. A. Selekcja obiektów po indukcionnomu parametru Geofiziczieskaja apparatura, Nedra nr 63. Leningrad 1978      
Kaufman A. The Modern Divinnig Rod Radion News April 1947 pp 41-43 and 126    
Keller G. V. Electrical methods in geophysical prospecting Pergamon Press Oxford 1966      
Kiegert R. Build a Metal Locator Popular Electronics 1980 nr 1      
Kimberley Jennings M Metal detector Elektor (GB) July-Aug. 1979 vol 5 no 7-8 pp. 77-8    
Kirpotin N N. Potylitsyn E A Study of the statistical characteristics of pulse metal-detector signals. .     Meas. Tech. (USA), Izmer. Tekh. (Russia), vol 38, no 5, May 1995. (USA) vol 38, no 5. May 1995. pp. 567-71, 4 refs, (USA) pp. 48-51.    
Klippberg, Olle Underwater Metal Hunting for Fun or Profit Radio-Electronics June, 1966 pp. 38, 39    
Kloska J. Projekt stanowiska do wyznaczania charakterystyk wykrywacza indukcyjnego Praca dyplomowa WAT1992      
Kraus K. Wykrywacz metali Elektor - Polska 2/95 1 page PLL NE 565 based MD +
Kraus Kamil Metalldetektor Elektor 7-8 / 92 p. 109 PLL NE 565 based MD +
Kuchnowski W. Metallsuchgerat Funkamateur 10/88      
Lagal Roy The Complete Vlf-Tr Metal Detector Handbook Ram Pub Co June 1979   ISBN: 0915920328  
Lahr W. "Coinshooter" Popular Electronics Aug. 1981      
Lahr William Hunting with A `Homebrew' Western & Eastern Treasures Jun. 1985 pp. 27-28    
Lancaster Donald E. Electronic Metal Locators, Basic Types and Design Factors Electronics World Dec. 1966 pp. 39-42 and 62. excellent revievs of operating methods (no P.I.), good text, many block diagrams +
Lee, Robt. D. Metallic Intrusion Detector System National Technical Information Service No. N70-41949/ 1970      
LeGaye, E. S. "Induction Balance Detector With Metal-Mineral Discrimination and Automatic Drift Correction Circuitry" in The Electronic Metal Detector Handbook West. Heritage Press Sep. 1969 and Mar. 1975 pp. 93-96    
Leslie, Eric How Mine Detectors Work Radio-Craft Jul. 1946 pp. 676, 677, 721    
Linington, R E A summary of simple theory applicable to magnetic prospecting in archaeology, Prospezioni Archeologiche 7 1972 9-59.    
Lowe A. J. The Revealer How to Build Gold & Treasure Detectors, by ETI 1981 p. 45-46 LC oscillator MD, one transistor (unijunction) +
Luck et al. The Prison Gun Detector Radio World Dec. 1936 pp. 50-56.    
Macario, R.C.V. Discriminative Metal Detector Wireless World Jul. 1978 pp. 43-46. controversial BFO with LED "target ID" +
Malagoli, S, Orlando, L, Pivo, S, and Rosso, F Location of archaeological structures using GPR method: three-dimensional radar acquisition. Archaeological Prospection 3(1), 1996 13-23    
Markus J. Modern Electronic Circuits Reference McGraw Hill Book Company 1981      
Masom R. A. The developememt, proving, and application of an in-line metal particle detecotr (MPD) Brit. J. Non Destruct. Test. 1985, 27, (3) pp. 159-166    
Miessner, B. F. Simplified Metal Locator Radio Electronics Sept., 1962 pp. 33-35    
Miller H. C. Inductance formula for a single-layer Circular coil Proc. IEEE 1985, 75, (2) pp. 256-257    
Mizjuk L. J. Elementy tranzistornych schem izmieritielnoj apparatury dla induktiwnoj elektrorazwiedki Naukowa dumka Kijów 1970      
Neville W Metal locators are fun-try one! Electronics Australia Dec. 1977. vol 39, no 9 pp. 70-1, 73-4    
Neville W. Metal locators are fun - try one! Electronics Australia December 1977 p. 70-74 simple BFO +
Newman, J. D. Metal Detectors for Police Use Proceedings Jul. 18-20, 1973 pp. 50-60 First International Electronic Crime ountermeasure Conf.  
Oksieńciuk W. Wykrywacze metali Świat Radio Kwiecień 1996 p. 51-55 short overviev, no plans +
Opel W. The PW 'Seekit' Metal Locator Practical Wireless May 1977, June 1977 p. 42-46, p. 117-118 BFO with auto tuning +
Osborne, W. E. Transistorized Metal Detector Electronics World Mar. 1962 pp. 86-88    
Owsley E C; Turner J M Precious metals detection technology          
Parker, Harry D. Transitone Locates Hidden Wiring "Radio Electronics Dec. 1960 p. 35    
Patel R. Medical metal locator   dissertation, Univ. Wales, Swansea.       -
Patent RP Układ elektroniczny do wykrywania metalu   WAT 1992.      
Pavlik P., Safar J. Absorpcni hledac kovovych predmetu Amaterske radio A 3/83 pp 92-94 simple one-generator MD +
Penfold R. A. Low Cost Metal Locator Everyday Electronics June 1979 p. 348-352 BFO on a 4001 +
Penfold Robert Simple Metal Detector Everyday Practical Electronics April 1998 pp 248-251 Q detector based on a TL071 +
Pertsev A. V. Optimum operating frequency of electronic metal detectors   Izv. VUZ Elektromekh. (USSR) no 1, 1971. pp. 54-8,.   -
Plunkett Malcolm J. Tools and techniques in radiometric exploration How to Build Gold & Treasure Detectors, by ETI 1981 p. 61-64 short reviev +
Potter John, Shields Bobbs How to Build Proximity Detectors and Metal Locators Merrill Co June 1972   ISBN 0672208814  
Przybysz Wiktor Wykrywacz metali Transet 150 Elektronika Praktyczna 7/95   IC BFO +
Rakes Charles D. Metal Locators         ?
Rakes, Charles D. Building Metal Locators: A Treasure Hunter's Project Book Tab Books Sept.1986   ISBN 0830605061 -
Rayer F. G. How to build Your Own Metal & Treasure Locators ETI Book Sales     book with practical details of simple heterodyne MD -
Rezler J. Radioelektronik     nr 4-5/1982    
Roston B. Developement of Locators of Small Metalic Bodies Jour. of IEE Dec. 1948 pp. 653-663.   -
Sadeh Y. Metal detector in a ferromagnetic environment.            
Samain M. D. Discriminative Metal Detector Wireless World October 1978 pp 57-58 (Comment to the Macario's Article) +
Silvester P P. Coccioli R. P . Multipole characterization and detection of metallic bodies Software for Electrical Engineering Analysis and Design. Pisa, Italy. May 1996 pp. 245-54, 9 refs. Author Affiliation : Dept. of Electr. Eng., McGill Univ., Montreal, Que., Canada.  
Silvester P P. Omeragic D .     Sensitivity of metal detectors to spheroidal targets.   IEEE Trans. Geosci. Remote Sens. (USA). vol 33, no 6, Nov. 1995. pp. 1331-5, 7 refs. Author Affiliation : Dept. of Electr. Eng., McGill Univ., Montreal, Que., Canada.   -
Silvester P P. Omeragic D . Sensitivity maps for metal detector design. IEEE Trans. Geosci. Remote Sens vol 34, no 3, May 1996. pp. 788-92, 8 refs Author Affiliation: Dept. of Electr. Eng., McGill Univ., Montreal, Que., Canada.   -
Sketeris R. Tri Mietaloiskatiela na mikroschiemach Radio 8/1990   (3 simple CMOS BFOs) (USRR) +
Sołtys Marian Wykrywacze elektromagnetyczne i ich zastosowanie do geodezyjnej inwentaryzacji przewodów podziemnych Skrypt AGH nr 672 Kraków 1978      +
Stanley John Earth resistivity meter How to Build Gold & Treasure Detectors, by ETI 1981 p. 40-43 primitive DC four-electrode meter +
Stanley M. John Exploration archaelogy - searching for our past How to Build Gold & Treasure Detectors, by ETI 1981 p. 36-39 short reviev of ground surveing methods +
Stuart Mark EE Treasure Hunter Electronic Projects no. 1 June 1994   simple PI +
Stuart Mark Microcontroller P.I. Treasure Hunter Everyday with Practical Electronics June 1994   no code available +
Szymanski, J E, and Tsourlos, P The resistance tomography technique for archaeology Archaeologia Polona no 31, 1993 5-32    
Tilbrook David Simple, sensitive Geiger counter How to Build Gold & Treasure Detectors, by ETI 1981 p. 55-59   +
Tkaczyk Zdzisław Wykrywacz metali Radioelektronik 1/85 p.23- off resonance +
Todd, Carl David Metal Detector Finds Ducts and Pipes Electronics Jan. 1, 1957 pp. 172-174.    
Traister Robert How to Build Metal/Treasure Locators Tab Books July 1977   ISBN 083067909X  
Traister Robert J. How to Build Metal/Treasure Locators Tab Books     ISBN 0830669094  
Wacławek R. Wykrywacz przewodów metalowych Młody Technik   s. 55-59 TTL based BFO +
Waddington D. BFO metal detector Wireless World april 1977 nr 1496. p. 45-48 simple BFO +
Wait Phil Pipe and Cable Locator ETI April 1980 p. 36-41 Two box (project 566) +
Wait Phil The 566 Metal Detecor Revisited ETI October 1980 p. 51-57 more details on ETI MD +
Wait Phil Simple Sensitive Metal Detector How to Build Gold & Treasure Detectors, by ETI 1981 (in ETI in March 1980) p. 22-27 Project 561, BFO +
Wait Phil, Harrison Roger A 'deep seaking' metal detector How to Build Gold & Treasure Detectors, by ETI 1981 p. 47-53 two box. Identical to other Wait's project +
Wales P. J. Sandbanks Metal Detector Practical Wireless Jan 1979, Aug. 1979 p. 47-51, p.65-66 complete P.I. project +
Wareham G. Discriminative Metal Detector Wireless World October 1978   Comment to Macario's Article +
Wareham G. Off-resonance metal detector Wireless World 1980 nr 1534 pp 47-49 theoretical discussion, not ready-to-go project +
Wąsowicz P. Wykrywacz przewodów Radioelektronik 1993/ 5 46    
Whitehead C. C. Metal Pipe or Wiring Locator Practical Electronics Dec.1976 vol. 12, No. 12 pp. 952-955    
Whyte Jennifer metal detectors - how they wok and how to choose How to Build Gold & Treasure Detectors, ETI 1981 p. 5-9 reviev (with some errors) +
Williams P. R Metal detector Practical Electronics (GB) April 1980 vol 16, no 4, pp. 65 (simple 140kHz detector)  
Wolff Steve< Evaluation of mechanical tester and comparison of Sentrie AT and Metor 120 metal detector performance Atlantic City, NJ Federal Aviation Administration Technical Center 1989 199 leaves : ill., charts, graphs,    
Wollner H Metal detector. Electronic keen nose Funkschau (Germany) march 1984 no 5 pp. 84-6 2 refs. (BFO type)