CTX 3030 What is under the hood?

[Skippy]

"The chip" ??
I guess you didin't see my earlier post. There's a board full of components. A pre-amp, an accelerometer, a microcontroller to identify the coil and give some security measures to dissuade copiers/aftermarket manufacturers, and I assume to transfer data from the accelerometer.
There's some pics posted on a Russian Forum (though I can't get it to load at the moment):
http://savepic.ru/6423805.htm
..taken from this md4u thread:
http://www.md4u.ru/viewtopic.php?f=94&t=9282

@Bklein:
I do have a faulty CTX coil (noisy and unstable, I recall), I see you're looking for one, would you be interested?

[Sean_Goddard]

My latest project uses FOUR Black Fin ADSP-BF607 DSP's, It's stupidly deep and Discrim is stupidly accurate but then it is a 16 channel "chirp" based system.

Won't be commercial I'm not interested in that.

[bklein]

Sean: that sounds amazing, sorry I can’t just put a delay on my post to let others see it up front for awhile.
Skippy: no I missed your related post due to its rather carefree description of what the reality is... that alone is enough for me to give up on hacking the CTX, life and electronics design has moved past my capabilities of making any improvements or experiments.
I also have an excal project going on... a guy sent me his coil that he was trying to repair... everything embedded in epoxy or whatever, he really trashed it trying to gain access to I/O connections. Probably same for the CTX. I did get an 11” coil with tabs broken off but it was better to fix it than tear it apart. I’d pay for shipping for yours but I have no confidence I could get it working or get access to coil connections without hosing it completely. :-)

[Chrisdw]

"The chip" ??
I guess you didin't see my earlier post. There's a board full of components. A pre-amp, an accelerometer, a microcontroller to identify the coil and give some security measures to dissuade copiers/aftermarket manufacturers, and I assume to transfer data from the accelerometer.
There's some pics posted on a Russian Forum (though I can't get it to load at the moment):
http://savepic.ru/6423805.htm
..taken from this md4u thread:
http://www.md4u.ru/viewtopic.php?f=94&t=9282

@Bklein:
I do have a faulty CTX coil (noisy and unstable, I recall), I see you're looking for one, would you be interested?

Some questions about the coil electronics
My assumption on the micro+ accelerometer is that direction of the swing matters and perhaps the relative speed as well.
Are all the signals to Tx and from Rx signal analog back up to the main pod or does the micro have any adc function?
Is there a serial data link from the micro or just a binary direction signal?

[Skippy]

There's serial data. As a guide, here's a teardown of the X-Terra coil, which will no doubt share some basic similarities with the CTX, including identification/verification:
http://www.geotech1.com/forums/showt...side-Schematic

The CTX definitely knows which direction you're swinging, as it can perform a display mode that shows detected targets in a 'left to right' graphical representation, which cannot be inferred without a sensor of some kind. But it's true, I think knowing search-coil speed could help the machine perform better, in terms of choice of filter coefficients, for example. It may also be viable to lower sensitivity at the extremes of each sweep, where false signalling can occur. Whether they actually do this or not is unknown. It's not that essential: in practice, the user learns how to sweep smoothly, and what sweep-speed works the best for the circumstances. The CTX will know the size of search-coil plugged into it, so could adjust signal gain, filtering parameters etc to cater for the different way different coils behave.

[bklein]

For the CTX, would one be able to replace the TX drive with their own generator and still have the detector function?
I'm oblivious to whether the TX signal is gated for RX to operate or if both can run simultaneously.
If they can run separately maybe you could try a fixed frequency of choice signal like many have asked for?

[FOMA]

Video in Russian. Two CTX3030 and E-Trac deviceswork on one coil minilab FBS800.The CTX3030 is connected to the coil via an adapter. Through this adapterYou can connect any coils to the CTX3030 that are made for E-Trac.Metal detectors work almost identically.

https://www.youtube.com/watch?v=ZlsPb9eCSp8&t=23s

[bklein]

I don’t know anything about E-trac coils - why them vs homemade coils? What about the accelerometer - is it in the Etrac coil and that’s why it was chosen? I’d really like a bigfoot coil for the CTX. Sure the CTX as it is blows away most anything with a bigfoot on it today for depth but depth isnt everything - when the wet sand isnt producing sometimes I use an xlt with a bigfoot and work the dry sand. I’m also hoping a custom coil can find gold chains. The 11” finds pretty small gold but just misses the chains. This adapter thing means it maybe possible to interface a pinpointer... Whats next with this guy - will he be sharing the details?

[FOMA]

Everything is known about E-Truck coils. They are made by various companies and radio amateurs. I also do the coils for E-Trac, such as in the photo. In this video there is all information, for those who are engaged in metal detector coils. Video tells that the coils E-Trac and CTX3030, the same. Only in the CTX3030 there is an electronic board. The windings are the same. If you make a coil for E-Trac and insert an electronic board into it, the coil will work with the CTX3030. And if you pull out the electronic board from the CTX3030 coil, it will be a coil for E-Trac. And if you make an adapter, then all E-Trac coils will work with the CTX3030. Written through translator.

[bklein]

So I need this adapter board. Do I have to take one from a working CTX coil or will it be for sale or design made public?
Thanks!

[FOMA]

It's very difficult to make such a scheme. Due to the presence of a controller it is impossible. The electronic board must be taken from the coil.

[bklein]

Do you have any tips on getting the board from the coil? An Excalibur coil has its board secured inside with what may be epoxy. I have one a guy tried to get access to and it was hopeless. I realize this board is different than the one in the CTX coil but just wonder if the CTX board is just as hard to remove.

[FOMA]

Electronic board CTX3030, in the coil CTX3030. The other is not.
In other coils, other circuits.
It is necessary to disassemble the coil CTX3030.
Carefully.

[bklein]

I about to obtain an 11" non-working CTX coil. How do I remove the board without damaging it?

[FOMA]

Carefully, nothing more to add.