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#1
05-30-2006, 08:39 PM
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Zahori op amps
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CA3130 has Ii = 5pA @ 15V and 2pA @ 5V, and en = 23uV. CA3140 has Ii = 10pA, and en = 48uV. Not sure whether this would make a significant difference in this application. When you're talking about pA, there are plenty of other sources of interference to swamp these minute values of current. 
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#2
05-30-2006, 09:38 PM
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Qiaozhi:
Extracted info: These are but a few of the low-cost operational amplifier models widely available from electronics suppliers. Most of them are available through retail supply stores such as Radio Shack. All are under $1.00 cost direct from the manufacturer (year 2001 prices). As you can see, there is substantial variation in performance between some of these units. Take for instance the parameter of input bias current: the CA3130 wins the prize for lowest, at 0.05 nA (or 50 pA), and the LM833 has the highest at slightly over 1 µA. The model CA3130 achieves its incredibly low bias current through the use of MOSFET transistors in its input stage. One manufacturer advertises the 3130's input impedance as 1.5 tera-ohms, or 1.5 x 1012 Ω! Other op-amps shown here with low bias current figures use JFET input transistors, while the high bias current models use bipolar input transistors. Extracted from: http://www.allaboutcircuits.com/vol_3/chpt_8/18.html
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#3
05-30-2006, 10:16 PM
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Quote:
 I would think there are many other factors (such a poor PCB layout) that would have a bigger effect on the performance than the difference between these two devices. Have you personally built this ion detector?
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#4
05-30-2006, 10:46 PM
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Yes, I built. In some part of my labo is the PCB, all with sockets. The PCB I make by own hand, no with PCB program, 10 years ago or more. I'll search and send here the photo.
Remember I try the 3140, but perceive that the 3130 is better, I don't know why. I have this in plastic and metalic (CA3130T).
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#5
05-31-2006, 10:23 PM
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pop
O.K. Esteban let's talk about Zahori for a while... some remarks...: - from your post"But in 1988 publish for positive and negative ions, looks that the zahori. Article in Spanish. You can replace the plate by antenna." Looking at the schematic you posted at the time i am not sure that 3130 will survive direct connection to BC547 which at the same time provide plate polarisation!? Is this correct? It will need some buffering and signal limitation at that point.... But, o.k. ...let's switch to the improved version you posted after that. First instead headphones you put a cap and audio transformer at the same time you omited scale. I do not think that output signal would be far enough to drive output transformer and provide at least some usable tone. What you can hear is some "clicking" hum generated from the 7555 due to poor filtering. About detection ....well, what we have here is a wide range "detection" of noises and "airborne" hum , chopped by 7555 stage under very strange, previously choosen, frequency rate!? I am absolutelly sure that this device will produce some noise but not sure at all that you can detect anything with it on longer range than 3-4 inches, and only if some powerfull source of "signal" is placed nearby. The very same problems occurs with ivconic's negative ion detector, although it is quite better design than zahori, at least it can detect strong ionic field if nothing else. O.K. I might be wrong considering this since i rely my remarks only on plain theory. I never built zahori so far. You made Zahori and i guess you do have some field experiences with it. Can you post here exact reports from it? "Hard head, RObert! Always I show you the path... electric field around conductive metals! And the electric field can be detecable by the Zahori, with the corrects modifications.." Thank you very much for "showing me the path"! Anyway....there is not any special electric field around conductive metals to detect! It is a fact! Esspecially no such field around burried metal, at all! There is for real an electrostatic field on the gnd surface and it has for real very frequent changes, minute after minute. Those changes i guess you can "detect" with zahori, maybe....maybe not...who knows? "electric field around conductive metals" can be obtained only if that metal is in the area covered by electromagnetic field generated by some source, that's how PI detectors do the job! So it is not logical at all that you can use zahori and do the job is claimed to do. But as i said, i never checked that in practice, i might be wrong.... I read this part again: "We will describe how to assemble several components to construct an instrument that is able to detect the variations in the electrical field, and indicate the ionic potential in the immediate environment." I cab beleive in that. But never mentioned any "conductive metals" at all! Only "variations in the electrical field". It means that you can realy use zahori to trace changes across some power line and simillar, and nothing else.... Further considerations are not important, device could work better or not - never mind. The point is that zahori is not usable in this subject of metal detecting at all. Sorry, but it is a truth! Besides i used so much 3130 and 3140 in my designs and i never noticed such big difference among them at all. So far as i am concerned, the 709 would do much better job than 3130 and 3140 in this design. Also some of newer rail to rail op-amps could be much better solutions here. But what is the point!? To check electric field variations you can do with some cheap "made in China" probes, you do not need to bug your self with zahori at all!? That's why i am using "obsolete" term here very often. I would like to see here some more interesting project on that subject. I would post it if i had, but i do not yet. I am not proponent and promoter of LRL, i am quite novice in that matter that's why i provoked you to post here some more.... But, after all, it seems that you too, do not have any usefull project to post here. Everything posted here man can assemble and check, than to beleive or not to beleive in some claims. Otherwise all ends with an empty retorics..... regards P.S. i hope this post is not offending you to much like in the past..... ha,ha,ha...
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#6
06-01-2006, 06:54 PM
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Regarding the ion detector for dual polarity, the both 4k7 resistence in base, one to negative load - reduces great the current, hope no motive for to think can burn the 3130.
Ok, in the Zahori, the 22 k controls the volume, note that in the original this is adjustable preset, no is fix in 22 k. So the volume is more high. Also you can up the 22 k, for example, to 47 k = more high volume. For to comprobe, you can ear the "hums" of the 4066 keys in the secondary (transformer) with earphones, but no connect yet any antenna, because in indoor is a "hell" (fluorescent lamps, cable, etc.). Adjusting the 10 k sens. pot. you can control the "hums" of the 4066 keys. The 10 k pot. put in the limit, in the start of the second stage audio circuit. This is a machine for indoor, far of electric lines and other interferences. So you put the most sensitive point with the 10 k of the Zahori. No synthetic clothes or plastic box for the instrument. I built in wood box (you can see in this same thread, page 2, the approximative model). Also Qiaozhi translate in English for all, in this same thread, the Zahori's text (0 views the both!)  .Of course, when you search with the 3 antennas instrument (indoor) you adjust with all the enviromental noise, internal ICs noise, 4066 "hums", etc. So over the level of the noise occurs the difference, this is the detection of the target. In some cases, noise is a reference wich put the "glitch" in delicate point, extremely sensitive. And the conductive buried target in the environment ups the microvolts in the antenna and sum. So, conductive items buried for long time has electrical field, no doubdt for me. Don't try the 709 in this circuit, but the very high input impedance of the 3130 is the theme. Also I redesign with 4047B as freq. generator and an only LM358. Works indoor, but I don't try in the field, yet. Report? The only report I have of third part that found a gross heavy gold chain 1 m depth and 30 m far. Other person found antique woman comb carey and gold with gem stones, another found 4 gold coins, this same person found old wire for fences, entire roll! So, this mass of rolling wire has some thing... Is so impressive the signal, is difficult to center the objects. The rest of the job is yours!  Here with the correct output: http://www.mytempdir.com/707825
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#7
06-02-2006, 06:14 AM
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hola esteban: mucho se ha discutido aqui de parte de lo escepticos, de que no es posible que un metal enterrado produzca un campo exterior que pueda ser detectado por un modificado detector ionico, quiero opinar, que segun yo creo y tengo entendido, el modo de que funciona esto, es asi:
primero :tenemos un sistema ionico en fragil balance, esto es cuando se calibra de tal manera que quede en el punto mas cercano de quiebre, seguno, se ha calibrado la vibracion ionica de tal manera que pueda ignorar las determinadas estaticas indeseables, o sea se ha modificado la ionizacion o sea el campo de actividad lanzada por medio de la antena, cuya señal es lanzada en rechazo por lo negativo del cono de aluminio o las dos antenas laterales, entonces tenemos una emision ionica lanzada , la cual lleva determinada indole, esta es lanzada hacia adelante, y al ser absorvida por los elementos idoneos, se produce un consumo o facilidad de mas facil descarga, pero los escepticos niegan que pudiera haber un halo ionico, arriba de donde hay un metal enterrado, yo creo que no han entendido el punto correcto, para mi., esa señal modificada no es simplemente iones de estatica, para mi esa señal si puede entrar bajo la tierra y ser absorvida la vibracion y hacer que el equilibrio del circuito cambie y dispare las alarmas indicadoras, tambien creo que si debe de haber un halo secundario de leve frecuencia siendo emitida desde el metal enterrado, y la explicacion es, que., todo metal son particulas en movimiento y por lo tanto en vibracion, y como toda actividad electrica produce campos, si creo que hay cierta emision de energia muy leve hacia el exterior, de todos modos no creo que sea ese halo ionico el que dispare o desequilibre el circuito del detector ionico, sino que ambos campos lo propicien, pero mas el la misma actividad energetica del metal, ya que todo es energia espero se me entienda y que tu esteban lo expliques en un correcto ingles, ok un saludo a todos y cuidense detectoman mexico hello they esteban: aqui from the escepticos has been discussed much, of which it is not possible that a buried metal produces an outer field that can be detected by a modified ionico detector, I want to think, that segun I create and have understood, the way that works this, is asi: first:tenemos a ionico system in fragil balance, this is when seguno is calibrated in such a way that it is in the point but near of it breaks, the ionica vibration has been calibrated in such a way that it can ignore the certain undesirable estaticas, that is has modified ionization that is the field of activity sent by means of the antenna, whose signal is sent in rejection by the negative of the aluminum cone or the two lateral antennas, then we have a sent ionica emission, which takes certain kind, this is sent forwards, and to the being absorvida by the idoneos elements, a consumption or facility takes place of but facil unloading, but the escepticos deny above that it could have I haul ionico, of where is a buried metal, I believe that they have not understood the correct point, for my, that modified signal is not simply estatica ions, for my that signal if she can enter under the Earth and absorvida being the vibration and cause that the balance of the circuit changes and shoots the indicating alarms, also I believe that if must of having I pull ahead secondary of slight frequency being emitted from the buried metal, and the explanation is, that, all metal is particulas in movement and therefore in vibration, and like all electrica activity it produces fields, if I believe that there is certain very slight emission of energia towards the outside, anyway I do not believe that he is that I haul ionico the one that shoots or unbalances the circuit of the ionico detector, but that both fields cause it, but but the same energetica activity of the metal, since everything is energia I hope is understood to me and that your they esteban you explain it in correct ingles, ok a greeting to all and cuidense they detectoman mexico
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#10
02-08-2011, 07:20 PM
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Mini Zahori
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According people wo build,they said distances around 20 m for big object.
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#11
02-08-2011, 09:50 PM
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When everybody says the same thing(has the same opinion) then the most probable thing is that this is the truth. If some say this and some say that then the only way to find the truth is only if you investigate it youself. This is why I decided to build it myself. Also another reason for this decision of mine is that I know very well that from all the people they build it maybe only a few have done it properly. One used a plastic box, one used something else than CA3140, one used long wires somebody else made it to work at 4.5V when above 4V is a problem and e.t.c,...e.t.c..... Even those that they followed the right path there is always the case that they didn't have a 'live' target to test it.Just going out looking at the so called "hot places" means nothing to me.Sorry but this is not a test. Apart from that I am a person that likes analysing something and getting all those small catches or hints to make the job perfect even when this is a project that small as the mini zaxori. I don't know why but I believe in Estebans words that somebody can discover treasure whith it.May be he knows something more or he knows what extra modification needed to add more detecting range to it.Anyway, whatever anybody can offer is great news for all of us and personally I respect it. Best whishes g-sani
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#12
02-09-2011, 07:31 PM
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LRL
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The Zahori build by Esteteban consist in complex antenna ,i even not try becouse find confused with Esteban´s information about telescopic antenna... I also like to analize the LRL performance of any LRL,but here my best spot is one gold medal buried more than 20 years ago,my first test place for old BFO and VLF detectors. Unfortunatly the treasures are rare here... Regards
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#13
02-09-2011, 10:09 PM
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Twenty years probably is not bad for a burried medal as a test target but weight is a factor as well.Even if this medal is 200grms I believe it is not enough in relation to the time it is burried. You are always invited over here to test any LRL you like in real conditions.Apart from your tickets everything else will be on the house. We will invite Geo as well! But I am sure he has done it allready(inviting you). Well you can always come together since we are only an hour apart by car. In any case I will make a video while testing so everybody will have an oportunity to see it working in the field. All the best g-sani
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#14
02-11-2011, 01:02 AM
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???
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Hello And you have some places where you think can be burried some treasures? You are from U.S.A or other country ? Its interesting to make TH in countries where its possible to do without breaking laws. Tanks for invitation. Regards
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Hybrid Mode
