GPR - project

[seagsm]

Thanks Seeker . Now I understandhow to buildit. I will try.

[Seeker]

Seeker,
I read a lot of articles about UWB GPR . But I have same problems . I can not build RF part .
And I decided that your project is more suitable for me for start. I can make transmitter and i have idea how to make antenna. The main difficulty is mixer. I have not any idea how to make PCB for SHF mixer. Can you explain in detail how to make it ?

Hi, UBW GPR is hard to do. You will need in some parts and instruments, which not be find easy.
So, to make mixer you mast find a splitter for satellite converter , to split signal between two receivers. It is from 900MHz to 2,1GHz, but still work up to 3GHz. Second thing is one old sat. converter for 5GHz or 10GHz band.
Inside you can find GaAs FET transistors.At last you need ferrite balun for output transformer.In fact you do not need PCB, you can solder elements on splitter board in box.Two F-connectors you can use for incomming signals,third for output signal, power supply mast get in through a duct capacitor.Incomming transformer is the same what is in splitter.Be very careful when solder FET's, they are sensitive on gate.The FET's mast be closely to the incomming transformer.

[seagsm]

Seeker,
I read a lot of articles about UWB GPR . But I have same problems . I can not build RF part .
And I decided that your project is more suitable for me for start. I can make transmitter and i have idea how to make antenna. The main difficulty is mixer. I have not any idea how to make PCB for SHF mixer. Can you explain in detail how to make it ?

Seeker,
I read a lot of articles about UWB GPR . But I have same problems . I can not build RF part .
And I decided that your project is more suitable for me for start. I can make transmitter and i have idea how to make antenna. The main difficulty is mixer. I have not any idea how to make PCB for SHF mixer. Can you explain in detail how to make it ?

[tesororockhound]

Seeker, I respect where you are coming from, but I think the whole point of this thread is to get the TH community together to build a working GPR. For example, I know a little about EE but my strong point is in Computer Science. I am willing to spend the time, which is a resource, putting together a computer GPR interface. Hopefully, if we get enough people together others can chip in or suggest corrections either to your GPR design or to the software.

By vaguely suggesting that others, who may not be experienced in EE, read through the thread and try to assemble the GPR, I think is counter productive. It would almost be like getting all the parts to a car and telling a non mechanically inclined person to assemble it with very limited instructions and knowledge.

Someone mentioned that they were knowledgable about antenna's, RF. If we all chip in and lay our cards on the table we can improve, and hone the design over time. At least that is my suggestion.

Otherwise, this noble project will fall to the wayside as others may not be knowledgable enough to assemble it, or inclined to pursue it if it seems the burden falls on a few people to accomplish the project.

[Gem Searcher]

"So I think about your idea of gem detections. All of gems have piezoelectric properties , If you send enough HV energy to them, they will begin ring with this frequency.For little depth I think this will work."

I've thought about that. Great idea. The necessary power consumption for a 6 hour search to 50cm depth might be a bit of a load to carry on ones back. Got to look at HV supplies that can be used as portable. Perhaps HV might work well.

Here's another thought that has crossed my mind. To find a way to detect and/or filter the gamma radiation signals from selected elements. You did mention THz using another form of energy than rf. Might also apply to your imaging sensor.

Thoughts?

[Seeker]

Hi ! It is excellent project. I want to build it but it is a pity I have not enough experience for building RF part. I can make digital and low frequence parts without any problems.
Can somebody help me to understand how to make RF part?

Read this all thread, if you have questions , I will answer in details.
It isn't for beginners, but if you have enough goodwill , you will make your GPR.

RF part of GPR have two different ways to be build. First is pulse type, where you send short pulses and measure time to return; second is sending modulated continuous signal and measure difference between sending and receiving signal.

[Seeker]

Making RF circuits isn't all that difficult. But not enough room here to explain it all. There is a lot of information on how-to and schematics out there. Just run a search for rf transmitters or schematics. You will find that the trickiest part of it is tuning the device in the frequency that you want it to operate.

Seeker, if you are still looking here, I haven't forgotten about our discussion. Still working on some education. But I've about reached the point that I might need more than I can get locally. Looking for some info on the "other than rf" that we were talking about.

Hi, I am still here. I have much then enough work, sorry for delay.
So I think about your idea of gem detections. All of gems have piezoelectric properties , If you send enough HV energy to them, they will begin ring with this frequency.For little depth I think this will work.

[tyson]

try to help us

if you have enough information to build GPR try to help us , for me i need from A to Z

[tyson]

try to help us

Making RF circuits isn't all that difficult. But not enough room here to explain it all. There is a lot of information on how-to and schematics out there. Just run a search for rf transmitters or schematics. You will find that the trickiest part of it is tuning the device in the frequency that you want it to operate.

Seeker, if you are still looking here, I haven't forgotten about our discussion. Still working on some education. But I've about reached the point that I might need more than I can get locally. Looking for some info on the "other than rf" that we were talking about.

if you have enough information to build GPR try to help us , for me i need from A to Z

[tesororockhound]

OK, I'm in for the software part, as long as someone helps me

[Gem Searcher]

Making RF circuits isn't all that difficult. But not enough room here to explain it all. There is a lot of information on how-to and schematics out there. Just run a search for rf transmitters or schematics. You will find that the trickiest part of it is tuning the device in the frequency that you want it to operate.

Seeker, if you are still looking here, I haven't forgotten about our discussion. Still working on some education. But I've about reached the point that I might need more than I can get locally. Looking for some info on the "other than rf" that we were talking about.

[seagsm]

Hi ! It is excellent project. I want to build it but it is a pity I have not enough experience for building RF part. I can make digital and low frequence parts without any problems.
Can somebody help me to understand how to make RF part?

[tyson]

what about pc programme

i thank you for last input... I think it's a GREAT project. but we need list of parts and what about pc programme

To Gem Seeker

I have been thinking about the same thing you are trying to do for some time now. It would definitely be nice to have an instrument that could detect gems. Curious how your efforts have been in constructing such an instrument? Cheers.