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Hi unregistered,
Yes, antenna will be included in the package of 3500 euro.
Yes, antenna will be included in the package of 3500 euro.
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Originally posted by Valchev View Post
hi valchev,
what will be the appropriate time windows for the 660 Mhz antenna? 50, 100 or 200?Comment
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Hi,
I am tested that with the 650MHz antenna GPR can to locate a big for this antenna cavity 1x1x2m in rock (limestone) on depth 1m. I suppose that the maximum depth for the 650MHz antenna will be 1.5m for cavity with a flat ceiling 1.5x1.5m in rock (limestone) . Limestone have a Relative dielectric permittivity (RDP) from 4 to 8, and the GPR will receive the reflected impuls after from 20nS to 30ns for depth 1.5m. The soils have Relative dielectric permittivity from 5 to 18, but maximum depth for the 650MHz antenna will be not more than 1m (soil have more attenuation) and GPR will receive the reflected impuls after from 14nS to 27ns for depth 1m. Due to this the time window (TW) must to be 50nS.
TW>D*2*3.3*(SQRT(RDP)) , nS
TW - time window - nS
D - hypothetical maximum depth of the object - m - meter
* - multiplication
2 - because the pulse travel >2*D
3.3 - nS/m - for 3.3nS pulse (and light) travel 1m in vacuum(~in air)
SQRT - square root
RDP - Relative dielectric permittivity of a middle(soil or rock)Comment
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Originally posted by Valchev View Post
thank you valchev,
so 50ns will be used....how about the resolution...for example 1 cubic meter cement vault is being scanned with the 650 MHZ antenna, can the iron rebar in the cement be seen on the screen, assuming there is a rebar at 0.5 meter?
thank youComment
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Too much money for cheap knock-off
Why would anybody pay $35,000 US for a low quality, Chinese made imitation when we can by a field proven, high quality, US made GPR system for $20,000 US??Originally posted by wendy View Post
Thanks but no thanksComment
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I have NOT made experiments with similar objects, and I can only to suppose. If a rebar means a fixture , I suppose if in a cement have 2 or 3 rebar on distance more than 0.4m(between rebar), GPR will can to locate, if the rebar are more I do not know. If you have an serious interest, I will test, but not soon. The antenna 650MHz is new, and not tested enogh yet.so 50ns will be used....how about the resolution...for example 1 cubic meter cement vault is being scanned with the 650 MHZ antenna, can the iron rebar in the cement be seen on the screen, assuming there is a rebar at 0.5 meter?Comment
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yes please, do some test....i have a serious interest, ...supposed a cement concrete block 1 cubic meter has a solid metal bar in the middle (no rebars), only one solid metal bar, measuring 1 by 2 by 6 inches, can this be detected by your gpr...especially the 650MHz antenna....Originally posted by Valchev View Post
Thank you.Comment
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Excuse me, I thought that it be about a long object (as pipe). GPR can not to locate object 1 by 2 by 6 inches on depth 0.5m = 20 inches. If the object is parallel to the antennas, GPR can to locate object in a medium with low attenuation and low conductivity with dimensions width Xm and length Xm at a depth 2*Xm. If the attenuation and conductivity are more, the depth is smaller.yes please, do some test....i have a serious interest, ...supposed a cement concrete block 1 cubic meter has a solid metal bar in the middle (no rebars), only one solid metal bar, measuring 1 by 2 by 6 inches, can this be detected by your gpr...especially the 650MHz antenna....
You can to see how to calculate the maximum depth depending from the size of object (resolution) from:
http://www.colchestertreasurehunting.co.uk/GPR.htm
The cement have RDP=5
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I don't agree with you !!!!!!!
Originally posted by Unregistered View Post
Have you come to examine it already ? all things are based on the fact.Comment
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Yes, I have examined the $20,000 US GPR system made by GSSI and it is made of the highest quality. Very rugged and well field tested and manufactured by a company that has been in business since the 1970's....for $15,000 less than the latest "fly by night" GPR manufacturer mentioned above.Originally posted by Unregistered View PostComment
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GPR TYPE GSSI
Hi,
Anybody knows GPR type GSSI? Thanks.Comment
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to Valchev :
Hello, I am interested to buy a Gpr of yours but for deeper depths. Me and my team have huge treasure case here in Greece. Is about a ancient gold mine. So a cave system inside the mountain, with many rooms and corridors with tones of gold, The entrance to cave is closed "from inside probably".I know that the "army team" had search for an entrance with negative results. Recently I have locate the "exit" but is vertical and blocked also. Before I start unblocking the exit to reach the inside rooms Me and my team need a deeper searching tool. Can you make it to scan 30-40 meters depth? I 'll pay more.Comment
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Hello SoK,
I can make a low frequency GPR that will scan on 40m , but it will have biger antennas (You will work with difficultys) and GPR will can to locate on depth 40m a room with width 20m and length 20m, or corridor with width 20m. I think that a real rooms and tunnels are not so large and this GPR will be useless. The GPR can detect cavities in rock with dimensions width Xm, length Xm, height Xm at a depths 2*Xm.
Why it is so ??? I will answer with quote from http://www.sensoft.ca/faqs_frame.html
“How deep can You see?” is the most common question asked of ground penetrating radar (GPR) vendors. While the physics is well known, most people new to GPR do not realize that there are fundamental physical limitations.
Many people think GPR penetration is limited by instrumentation. This is true to some extent, but exploration depth is primarily governed by the material itself and no amount of instrumentation improvement will overcome the fundamental physical limits.Comment
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So what is your suggestion? To use a regular gpr? Will the vlf waves will help?
I need to find a corridor to follow it from above the mine. I know only the side of the mountain when the entrance was open.
Look I am not a rich man and I can't afford to buy an OKM detector. Look we can make a deal. If you think you can help us here by selling us a working machine in reasonable price, we'll buy it. But if we won't be helped with your detector, I ll return it back to you and you will give me back my money.(we can sign a contract for that). Or you can come here to our site and work with us and your equipment to find the entrance and take your share. I know that sounds dangerous in your mind but think about it. there are many tons of gold down there for all. We are not professionals treasurers or thiefs. We are working people that happens to learn about that case.
cheersComment
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