IN 1980-81 (B & W PHOTO)

[Esteban]

Close-up of long distance radar MD for gold and silver. Miguel MontanÃ*a Grinok (my cousin), with the detector. Many of the photos I'm colected have secuences.

The apparatus sometimes detect copper, nickel and bronze coins, but only at very short distance, two or three meters, but gold and silver coins, rings, etc., was detected at 30-50 m, and the depth is no problem, easily 2 or more meters. The only time I see to detect bronze coins at 10 meters from the detector had explanation: in the place we found 12 good quality bronze coins.

If I decide to publish a book under the title, for example, "The parallel history of metal detection" (with many photos), will be success? Any idea from your part? There are publisher in USA for this?


Some years ago, this kind of SIMPLE apparatus are dismantle for to keep the secret. My first trip was in December 1979 (had 20 years old!) and we found many objects, include a small treasure consist in 55 pieces of gold and silver jewels and gem stones.


Wait no disturb my intromission. Please, if disturb, let me know.


Sincerely,


Esteban

[okantex]

Hi Esteban
Do you have a schematic of this kind of radar based MD?
good days

[Esteban]

No, but basically is a stable BFO, radio, alarm, classifier... Here the crude parts:

[hung]

Hey Esteban,

Is that Mr. John Baldwin with your cousin?

[Esteban]

Hi Hung. No, here is Mr. John Baldwin in this 2 photos:

[Geo]

Very Good.
But ... where are you Esteban ???:) :) :)
Regards

[hung]

Thanks Esteban. Nice to see the man...
According to Damasio he died of serious nervous breakdown due to sorrow and disapointment.
Alonso told Mel Fisher in 1984 where the Atocha's motherload was. That is, the region where it was. He was using a prototype of the DCH85 back then.
After Fisher found the load Baldwin, who was Alonso's partner and Alonso himself were expecting some kind of reward and recognition. None of both were given. Not a single 'thanks'.
That's why Damasio said Mel Fisher was a bandit.
I agree.

[Esteban]

Hi Geo

I'm in other "actual" photos. I knew very well Mr. John and the team. Maybe there are some photo of this epoch with me lost in some part... Here, trying two experiments:

[Esteban]

Hi Hung

Yes, I ear this history and how Mr. Fisher invit them for to dinner and how the credit card of Mr. Fisher was rejected, not fund... so Mr. John assume the cost of the "invitation"... :mad:

[okantex]

Hi Esteban
I am just asking to learn about theory.
After you said this device works with BFO ,I read some pdf file in geotech archives.ther it is told that BFO type detector are good in discrimination but bad in dept penetrating.generally 20-30cm .but you say it detects from 50m away and 2m and more dept.
Could you please explain how can it be.And trnsmitter(one which looks like hairdryer) coil looks different can you tell about its windings .does windings make it to affect farther and deeper.
thanks
okantex

[Esteban]

Before emit the BFO an only hertz, the amplification enlarge this "soft breeze". With this type of detector (I had one of 80's generation) I found a copper plate 120 X 60 cm (very big) at 50 meter distance and 1.5 meter depth with a coil of 11-12 cm diameter.

The old coil I saw was turn by turn, but other models has classic winding. The BFO is a transmitter since is an oscillator and at the same time is a receiver, so attention with the "obsolete". :D

Here exactly the middle and the end of 80's pistol I had:

[Radioactive]

Well the one in his hand is a receiver with a Linz spider antenna
http://img172.imageshack.us/img172/2733/silk1ir1.jpg

These have been used for many years in old crystal sets as a receive antenna. Yes they have some directivity, but only at 180 degrees out of phase. I wound these a lot as a kid, and there are many other type of weaving of the antenna wire. You need a jig to do the weaving of the linz wire. Just my two cents.

[okantex]

Hi Esteban And Radioactive,
Esteban
the antenna that radioactive sent .Can it create such a long magnetic area and cause eddy currents which can cause inducation back.
or does it work like radar.can induced target cause reflection(like produced by selonoids)
Radioactive
do you have other antenna pictures works like this.especially using U cores.
thanks

[okantex]

Esteban
about the one in your causen's hand
does it have a coil inspider configuration.the front part can not be seen identically in pics.and I wonder does it have another coil winding at the bach where causen holds.that part is too big for just batter and circuits.

[Esteban]

The detectors showed here has normal coils. I never see another kind of coil, example type spider.

Works like a radar, but detects microvariations in the adjacent ambit.

[Geo]

Before emit the BFO an only hertz, the amplification enlarge this "soft breeze". With this type of detector (I had one of 80's generation) I found a copper plate 120 X 60 cm (very big) at 50 meter distance and 1.5 meter depth with a coil of 11-12 cm diameter.

The old coil I saw was turn by turn, but other models has classic winding. The BFO is a transmitter since is an oscillator and at the same time is a receiver, so attention with the "obsolete". :D

Here exactly the middle and the end of 80's pistol I had:

Hi Esteban.
Perhaps if it published the schematic of this 80's detector in forum it was found guys that would make good and intelligent modifications so that it becomes enough better:) . You do not know some time what becomes:rolleyes:
Regards

[gold24h]

I would like to build one of these,what frequency does the transmitter transmit and the receiver receive?

[okantex]

Hi Estebanif this pistol detector is a kind of BFO
where is the reference oscilator coil?
and why why there is a antenna in radio part.
and does it work when it is turned to ground(what we do when pinpointing with mineoro)I wonder its dept penetration in this position.

[Esteban]

Hi, the reference coil is in the black head.

In the radio is the called "classifier".

[okantex]

Excuse me ,I am just tryiing to learn about electronics you know.
if refrence osc. in black )also beat osc must be in bleck because it is the one we use in bfo),so what is the antenna for in radio ?
clasifer must get signal from beat osc. ,if not what is the cable for between black and clasifier?

[Esteban]

Search coil is the front, the circuit is in the black head, include the fix oscillator with his coil. The zero is make with precise tandem. This circuit is linked to the aluminium box with the shielded cable, in where is the radio and classifier control with potentiometer.

Variations there are severals, but the principle is equal in the major part.

[gold24h]

Can anybody explain how this works,does it resonate the buried metel.The black part must be a transmitter,it is possible to transmitt a signal in the air at say two watts power and receive the signal at a mile or more for mhz frequency range,but how could the signal go from the air then enter the ground where the metel is and cause it to resonate.If the metel was truly resonating you could receive the resonated signal from a mile away with a good receiver.